Plague in seventeenth-century Europe and the decline of Italy: an epidemiological hypothesis

Abstract

This article compares the impact of plague across Europe during the seventeenth century. It shows that the disease affected southern Europe much more severely than the north. Italy was by far the area worst struck. Using a new database, the article introduces an epidemiological variable that has not been considered in the literature: territorial pervasiveness of the contagion. This variable is much more relevant than local mortality rates in accounting for the different regional impact of plague. Epidemics, and not economic hardship, generated a severe demographic crisis in Italy during the seventeenth century. Plague caused a shock to the economy of the Italian peninsula that might have been key in starting its relative decline compared with the emerging northern European countries.

Introduction

In recent years, there has been a resurgence of interest in the plague. It is now known that not all medieval and early modern plague waves shared the same characteristics.¹ Important changes have been described, showing the evolution of plague from universal killer at the time of the Black Death to a more focused disease. However, a better understanding of its epidemiology is required to re-evaluate the differential impact of this disease, both from one plague wave to the other, and from area to area. This article contributes to this end, providing new data and new methods. Drawing upon the considerable information collected about Western European plagues, and a new database concerning Italy, the article shows that epidemics struck the south of the continent much more severely than the north. Italy, for example, faced the most virulent plagues since the Black Death. The distinguishing variable was not local mortality rates, as extreme epidemic mortality occurred in many parts of Europe. Instead, it was the capacity of plague in the south to infect pervasively vast areas, affecting villages and hamlets as well as cities. This variable, territorial pervasiveness, has never been studied before.

Territorial pervasiveness determined not only the demographic effects of plague but also its political-institutional and economic consequences. The stricken population was unable to recover quickly, so epidemics had long-lasting effects in terms of total produce levels and fiscal capacity of the country. This article argues that the strength of epidemics affecting seventeenth-century Italy, unparalleled elsewhere in Europe, is a main factor in the relative decline of Italian states in this period. Section 1 provides an overview of European plagues during the seventeenth century. Section 2 focuses on Italy and on the plagues of 1629–1630 and 1656–1657. Section 3 formulates hypotheses about their demographic and macro-economic consequences and proposes an agenda for future research.

1. The varied impact of plague in seventeenth-century Europe

Apart from the Black Death of 1347–1350, studies of single plague wave have usually been limited to small areas, sometimes reaching the national scale but failing to provide a European perspective.² For the late medieval and early modern waves, the main source is still Biraben's database. Based on collections of annals and chronicles, the database enumerates localities affected by the disease, year by year, across the continent (Biraben 1975, vol. I, p. 363–449). Biraben aimed to reconstruct the chronology of plague waves identifying the worst episodes, a task he accomplished masterfully. However, his database has been instrumental in establishing the idea that overall plague was an egalitarian killer: striking now one part of Europe, now another, but in the long term inflicting similar damage on the different areas.

The correct use of Biraben's data is to identify plague waves as short-term increases in the number of places affected. Turned into quantitative measures such as those presented in table 1, however, they may prove misleading. In particular, they suggest the following:

1. in the sixteenth and seventeenth centuries, north-western Europe (including France) was struck by plague at least as badly as south-western and central Europe;

2. plague struck the continent about as badly during the sixteenth century as in the first part of the seventeenth (up until around 1670–1680);

3. during the second half of the seventeenth century, plague began to retreat from Europe, albeit with a different chronology according to the area considered. During the eighteenth century, epidemics of plague became rare and the area affected more limited.

Table 1.

Number and time distribution of plague outbreaks in Western Europe, 1500–1749

	Spain and Portugal	Italy	France	England, Scotland, and Ireland	Belgium, Low Countries, and Luxemburg	Germany, Austria, Bohemia, and Switzerland
1500–1549 (%)	21.4	42.0	29.8	14.3	15.6	19.8
1550–1599 (%)	36.7	22.6	30.6	28.5	26.8	24.4
1600–1649 (%)	22.1	19.6	33.4	46.1	36.9	37.1
1650–1699 (%)	19.9	13.5	4.9	11.1	20.7	16.1
1700–1749 (%)	0.0	2.3	1.3	0.0	0.0	2.5
1500–1749 (%)	100	100	100	100	100	100
1500–1749 (n.)	458	438	2148	1355	358	902

Note: own elaboration from data published in Biraben (1975, pp. 363–374)

These conclusions are all part of the received wisdom about plague. This article suggests a deep revision of the first conclusion. Although the second and the third will not be assessed here, a brief discussion is necessary. Regarding the second, for France Biraben listed four “strong waves” of plague during the sixteenth century (two of which after 1550) and only one for the seventeenth (the epidemic also affecting Italy in 1629–1630). For north-western Europe in general, in the sixteenth century, strong waves rise to five and in the seventeenth to two (Biraben 1975, pp. 119, 125). This conclusion is probably correct; nevertheless, it can be misleading. In Italy, for example, plague epidemics were certainly more common in the sixteenth century than in the seventeenth, but these episodes were much more limited than the catastrophic plague waves of 1629–1630 and 1656–1657. The latter had an impact much greater than all the sixteenth-century plagues taken together (Alfani 2010a, 2013). A general indication can be drawn: frequency of severe plagues in a period is not always a good proxy for plague intensity.

The third conclusion, about the retreat of plague from Europe, is undoubtedly true. Many explanations of this still-mysterious process have been suggested: mutual adaptation of man and pathogen; improvements in sanitation and hygiene; better control of epidemics; variations in the population of vectors of the disease (rats or other) (McNeill 1976; Appleby 1980; Del Panta 1980; Slack 1985; Livi Bacci 1998). Lastly, climate: a factor mentioned by some early authors, which has recently been re-proposed as a key variable to understanding medieval and early modern epidemics (Woehlkens 1954, pp. 139–148; Biraben 1975, pp. 134–139; recently Campbell 2010a, b). The new data presented in the next section are also relevant to this debate.

After many years, Biraben's database inevitably needs updating. Instead, it has been used for aims that go well beyond the original ones. An example is Duncan and Scott's attempt to study “large-scale metapopulation dynamics’” solely on the basis of this information. Their conclusion that France had been the “focus and epicentre for the plague in Europe from the time of the Black Death to 1670” (Duncan and Scott 2004, pp. 286) is almost certainly wrong, due to over-representation of France in Biraben's database. More generally, none of the works using Biraben's data detected the uneven way in which plague struck Europe. This is because the territorial pervasiveness of each epidemic cannot be evaluated correctly by using “frequential” data, originally meant simply to reconstruct the chronology of plagues.

To show that seventeenth-century plague affected distinct areas differently, this article focuses on Western Europe, the theatre of the shift of the balance of economic power from the Mediterranean to the north. Interestingly, during the century, the fastest-growing areas were those less affected by plague. The analysis makes use of the most recent studies related to each area and, for Italy, integrates findings from a new database (see section 2). However, the quality of available information is not even across Europe, and for no area is the information as accurate as that provided by this article for Italy.

One might think that the best way to compare plague intensity in different areas during a given period is to compare mortality rates. However, during the seventeenth century, most regions of Europe were struck by more than one plague wave (Italy, where plague waves did not overlap, is the most notable exception). The mortality rate of each single wave cannot be summed, as the size of the reference population changes from one wave to another. Therefore, table 2 provides information about the number of plague victims in different areas over the whole century and compares this to the population existing around 1600 to produce estimates of “share of population lost,” taken as roughly indicative of overall plague intensity.

Table 2.

Plague intensity in Western Europe during seventeenth century

Country/region	Plague victims (millions)	Percentage of population lost to plague
Italy (Kingdom of Naples)	0.87–1.25	30–43
Italy (north)	2.00	30–35
South Germanya	not available	20–25
Dutch Republic	not available	15–25
Spainb	1.25	18–19
France	≥2.20	11–14
England and Wales	0.45	8–10

^aSouth-West Germany including Rhineland, Alsace, and part of Switzerland.

^bThe estimate for Spain includes the 1599 epidemic, which accounts for about half the victims.

Sources: author's elaborations for North Italy; Fusco (2007, 2009) for the Kingdom of Naples; author's elaborations for Europe, based on the literature cited in this article.

If we accept the higher estimates provided for northern Italy and the Kingdom of Naples and consider that the lower estimate of around 30 per cent provided for the latter seems to be a reasonable estimate for central Italy, then no other area of Western Europe came near to the overall losses suffered by the peninsula.³ The closest is southern Germany, with between two-thirds and one-half of the losses in Italy. England and France sustained only one-third or one-fourth. Given the high population density of the peninsula, the difference in the total number of plague victims is equally great: ∼450,000 for England, compared with two million for northern Italy.⁴

These figures are even more striking, considering that in Italy they relate to a single plague wave, whilst elsewhere they are the cumulative effects of many epidemics. Overall, they tell a different story from that indicated by Biraben's data. The fact that plagues became more frequent in north-western Europe during the first half of the seventeenth century while in the south their frequency decreased (table 1) does not go hand in hand with changes in plague intensity. Instead, the areas of Europe where plague caused more victims were those where plague waves became less frequent.

The main reason why Biraben's data do not allow to evaluate correctly plague intensity is that they do not really inform us of the territorial pervasiveness of the infection. The occurrence of repeated outbreaks in the main cities of countries like England (see below) does not tell much about the ability of the disease to spread to rural areas. Territorial pervasiveness can only be measured correctly as the proportion of communities affected over the total, from which probability of contagion can be deduced. Section 2 provides this information for Italy, but such data are not available for other regions of Europe. Consequently, current literature only allows for a provisional analysis.

Figure 1 shows where and when plague struck, dividing the century into four 25-year periods. The coloured areas are those where epidemics affected thoroughly a territory; isolated cases have not been represented in order to reveal where the disease manifested a degree of territorial pervasiveness. Among the areas included, only Austria and south-eastern Spain experienced plague in the last quarter of the century: the time of the “Great Plague of Vienna” (1679) killing ∼76,000 residents of the city. The second quarter of the century contrasts strikingly with all others for the large-scale diffusion of plague epidemics, covering most of Germany, half of Italy and much of France and Spain as well as the main urban clusters in the Netherlands and England.

Figure 1.

Plague in Western Europe, 1600–1699. Sources and notes: reliable maps allowing to evaluate whether a territory was infected pervasively in a given period are available only for England, central Europe (Germany, Austria, Switzerland, and western Poland), and Italy (provided by Wrigley and Schofield 1981; Eckert 1996; and by this article for Italy). For the rest of Western Europe, the reconstruction remains partly conjectural. For France, I mostly relied on maps published in Histoire de la population française (especially Biraben and Blum 1988). For Spain, Perez Moreda (1980, 1988). For the Netherlands, Flanders, and Hainaut, Van Bath (1965); Van Werveke (1965); Arnould (1965); Rommes (1990). Note that for Spain, the map does not include the plague that affected the central and southern part of Iberia in 1599, even if somewhere it ended in 1600 or 1601.

Figure 1 shows clearly a key difference in seventeenth-century European plagues:

1. in the north, plagues affected mainly highly urbanized areas, while in the south, they had much greater territorial pervasiveness spreading more effectively to the countryside;

2. in the north, different plague waves affected repeatedly the same places, while in the south, areas affected by one wave were usually spared by the following ones.

These differences between north and south appear only in the seventeenth century. In the sixteenth, also in southern Europe plague was mainly an urban affair and separate waves struck the same place every few decades. This hints at transformations in the epidemiological, and maybe also biological, characteristics of plague (section 2).

Even if these results have to be considered provisional until territorial pervasiveness of plagues is measured precisely across Europe, they are consistent with the findings of regional studies. In England for example, “in the seventeenth century plague became relatively rare except in large urban centres and, when it occurred, was often an accompaniment to a major epidemic in London” (Wrigley and Schofield 1981, p. 668). This would be the case for all of the worst epidemics of the century, in 1603, 1625, and 1636, as well as for the more localized outbreak of 1665–1666, which ended with the Great Fire of London (Slack 1985, pp. 68–69). For England, we also have some measures indicative of low territorial pervasiveness. Between 1565 and 1666, 43 per cent of the parishes in Devon did not suffer from an epidemic of plague (as measured by a doubling of burials or more), while in Exeter, the same measure rises to 45 per cent. Focusing on market towns, the proportion of places spared falls below 21 per cent (Slack 1985, pp. 109–110). These figures are impressive, given that if calculated for northern Italy in 1600–1657, overall they drop to 9 per cent (see below): one-fifth the figure for England, and considering a time period half as long. This was probably also the case of most central and southern regions of Italy, as well as Germany.

Something more should be said about the main plague waves affecting seventeenth-century Europe. While in the north, the situation of England is also representative of the Netherlands (Flanders and Hainaut included), where plague was mainly an urban affair striking repeatedly the main cities but mostly sparing the rural areas,⁵ in the central and southern part of the continent, most of the plague damage was due to a small number of great plague waves. The most severe began on the shores of northern France, in the Netherlands, and in Renania around 1623, struck England in 1625, and in 1625–1626 infected central Germany. In the following years, it moved southwards, through southern Germany and eastern France. In 1628–1629, it was covering the area between the Pyrenees and southern France on one side, Bavaria and Switzerland on the other. In late 1629, it entered Italy, ravaging it in 1630 (Eckert 1978). From Lombardy, under Spanish rule, the plague spread to Catalonia.

For southern France and northern Italy, this is considered the worst plague since the Black Death. This may also be true for other regions, like Germany, but there the plague effects are not easy to distinguish from those of the Thirty Years' War, since troops acted as disease carriers infecting vast areas (Alfani 2013, pp. 43–4). Another important plague wave ravaged Andalusia, the Balearic archipelago, and the rest of the Spanish Mediterranean in 1647–1654. This was the worst plague striking Iberia in the century.⁶ In 1652, it spread to Sardinia, and in 1656, through Naples, to most of southern and central Italy.

2. Italy: an exceptional case

“The spectre of plague loomed as large in seventeenth-century England as it did in contemporary Italy. True, even the worst English epidemics in this period seem to have been somewhat less lethal than the two Italian outbreaks; but then their frequency was much greater.” In this way, Helleiner (1967) introduced his comparison of Italian and British epidemics, pointing out correctly a difference in their frequency, but also suggesting that the total demographic impact was roughly the same. This still-widespread idea needs revising, taking into account a previously neglected variable: territorial pervasiveness. Before doing this, though, a general picture of plague in the peninsula must be provided.

2.1 Plague waves in early modern Italy

During the sixteenth century, Italy had suffered relatively little from plague. Even the worst epidemic, the “San Carlo” plague of 1575–1577 that struck many important cities in the north, had been mainly an urban event involving a limited area. The damage it caused was quickly mended thanks to the availability of a large surplus population in the countryside (Alfani 2010a, 2013). There would be no such surplus after the two great epidemics of the seventeenth century. The first began in October 1629, when Spanish and French troops involved in the War of the Mantuan Succession, entered the peninsula spreading the disease from areas infected since 1628 (section 1). During the spring of 1630, the disease spread quickly southwards and eastwards the infected territories of the Susa valley and the lake of Como, covering all of the north (save for Liguria and parts of Friuli and Piedmont) by the early summer and then spreading to Tuscany, but failing to go further (Del Panta 1980; Manfredini et al. 2002; Alfani and Cohn 2007; Alfani 2010a).

The second epidemic began in Sardinia in 1652, having arrived in Alghero from Spain. After ravaging much of the island, it landed in Naples in April 1656. Thence, it spread to most of southern Italy (the Kingdom of Naples); only Sicily and parts of Calabria and Apulia were spared. To the north, the epidemic arrived in Rome in June 1656 and then affected most of the Papal State, arresting its spread in Umbria and Marche. It did not penetrate the Granduchy of Tuscany, affected by the previous wave, but it did spread by sea to Liguria (it was present in Genoa from July 1656), which instead had been previously spared (Del Panta 1980; Fusco 2007; Alfani 2010a).

Among the Italian regions, only Sicily was entirely spared the two main waves. However, it had experienced a regional plague in 1624. Overall, the territorial integration of the seventeenth-century Italian epidemics is impressive. As apparent from figures 1 and 2, no known Italian communities were struck by more than one of these plague waves. Especially impressive is the case of Liguria, spared in 1630 when Piedmont and Tuscany were affected, and unable in its turn to infect these areas in 1656. On the micro level, only small areas around the towns of Rapallo and Finale were infected in 1630. Those same territories were the only parts of the region spared in 1656. The perfect match between the two epidemics does not allow for a simple “morphological-institutional” explanation of why the two plague waves did not overlap (as discussed later).

Figure 2.

Urban mortality rates during the plagues of 1629–1630 and 1656–1657. Sources and notes: places represented on the map only comprise those cities for which mortality rates could be calculated. For territorial coverage of different Italian plague waves see figure 1, as well as figure 2.1 in Alfani 2010a, p. 232.

2.2 Characteristics and composition of the database

Parish books of burials are rare before around 1600 (only the Rituale Romanum, introduced in 1614, established a duty for all Catholic parishes to keep them). Consequently, seventeenth-century plagues are the first that it is possible to study systematically with these sources. Other sources, the city books of the dead, have similar characteristics. However, while sometimes available since the fifteenth century, they exist only for some cities (for example Milan. Cohn and Alfani 2007, pp. 178–181).

The new database of north Italian burials used here includes 138 time series related to 101 different communities. Some communities, especially cities, had more than one parish recording burials. Only in three cases (Milan, Mantua, and Venice) have city books of the dead been used instead of parish registers. During severe epidemics, under-registration of burials may occur but usually this is either a minor disturbance given the diligence used in the records or a macroscopic event (especially if the parish priest died) resulting in a stoppage of the records that could last weeks or even months. All time series presenting serious gaps in the relevant years as revealed by simple completeness tests have been excluded from the analysis.⁷

The original registers are usually preserved in the relevant parish archive, sometimes in the diocesan archive. Direct reconstruction of time series from the original registers has been complemented with collection and digitalization of previously published data. The resulting database is adequately balanced from the point of view of territorial and political/institutional representation (see distribution per region and per state in table 3). It also allows for an unusually good coverage of rural areas given that about three out of four series are rural (see below).⁸

Table 3.

Structure of the database

	Single series		Communities
	Aggregate, n	Percentage of total	Aggregate, n	Percentage of total
Distribution of the sample by series starting date
Series starting before:
1550	3	2.2	3	3.0
1600	78	56.5	52	51.5
1610	104	75.4	74	73.3
1620	126	91.3	93	92.1
1627	138	100.0	101	100.0
Distribution of the sample by contemporary administrative region
Emilia Romagna	41	29.7	26	25.7
Liguria	33	23.9	25	24.8
Lombardy	27	19.6	19	18.8
Piedmont and Aosta Valley	21	15.2	17	16.8
Veneto, Friuli, and Trentino	16	11.6	14	13.9
Total	138	100.0	101	100.0
Distribution of the sample by Italian state (at 1630)
Republic of Genoa	29	21.0	21	20.8
Papal State	23	16.7	17	16.8
Duchy of Milan	21	15.2	13	12.9
Duchy of Savoy	20	14.5	16	15.8
Republic of Venice	17	12.3	15	14.9
Duchy of Parma and Piacenza	9	6.5	3	3.0
Duchy of Mantua	7	5.1	7	6.9
Duchy of Modena	6	4.3	3	3.0
Others	6	4.3	6	5.9
Total	138	100.0	101	100.0

The database is the largest collection of information about burials existing for early modern Italy. In 1624–1628, the average yearly number of deaths in the included villages, towns, and cities was ∼16.800. Around 1600, the population of the area was ∼6.5 million. Thus, hypothesizing a mortality rate of 30–35 per thousand in normal years, the database accounts for 7.4–8.6 per cent of all deaths.

A limited use will be made of a second database, containing information about mortality rates. This information comes from a variety of sources and is mostly related to cities, which makes it inadequate to measure territorial pervasiveness. This database, still being expanded, here is used only to provide examples and the data chartered in figure 2.

2.3 Mortality and territorial pervasiveness

The two large-scale epidemics suffered by Italy were characterized by very high mortality rates compared with those of the sixteenth century (Alfani 2010a), or to those affecting contemporary Europe. If a typical English epidemic had mortality rates of 100–120 per thousand (Slack 1985, p. 66), in Italy the most common was 300–400, with peaks of 500–600 per thousand. For example, the mortality rate was 330 per thousand in Venice, 443 in Piacenza and 615 per thousand in Verona in 1629–1630, and 490 in Genoa and 500 per thousand in Naples in 1656–1657. The situation could vary considerably from one city to another. For example, Tuscan cities in 1629–1630 were “lightly” affected, with a mortality rate in Florence of 137 per thousand. In Rome in 1656–1657, sanitary authorities proved very efficient at limiting the spread of plague; consequently the mortality rate was just 80 per thousand (Sonnino 2006). While higher estimates exist (187 per thousand: Cipolla 1981), Rome was certainly struck less badly than other communities of Latium, where mortality rates equalled 300–400 per thousand, with peaks around 600 per thousand (Ago and Parmeggiani 1990; Sonnino et al. 1999). Such variability is visible in figure 2.

The figure shows the prevalence in Italy of very high mortality rates, well above those most common across Europe. Strikingly, rural mortality was not inferior to the urban. In 1629–1630, it equalled 400 per thousand in Nonantola near Modena; 322 and 689 per thousand, respectively, in the villages of Madregolo and Cella near Parma; and 522 per thousand in Cerea near Verona (Ferrarese 2000; Manfredini et al. 2002; Alfani and Cohn 2007). Extreme plague mortality rates in the countryside are not unheard of.⁹ What is specific to the Italian epidemics is that there was a match between rural and urban communities not only in mortality rates but also in the probability of a community being infected. This led to exceptional territorial pervasiveness, with plague spreading even to the smallest country village. Isolation still offered some protection, but very few places escaped contagion entirely.

To illustrate this point, the argument will be set in the shape of an experiment, using the new database of time series of burials. Covering all of northern Italy, it allows to evaluate the territorial pervasiveness of the 1630 epidemic and even provides a control group: the Ligurian communities, where reportedly plague did not spread.

To check which communities were affected, a method developed by Del Panta and Livi Bacci (1977) has been used. They defined a mortality crisis as a short-term perturbation of mortality that reduces the dimension of the generations so much that they are unable to reproduce themselves entirely even making full use of their potential for recovery. A mortality crisis, then, happens when one generation is prevented from generating another at least equal in size, even when the rise in fertility and nuptiality that always follows a peak of deaths is taken into account.

A 50-per cent rise in deaths is enough to prevent the generation born in the year of the crisis from fully reproducing. This would be a “small” crisis. A 300 per cent rise in deaths could not be counter-balanced by the recovery potential of all of the generations under the age of 15 at the moment of the crisis. This would be a “great” crisis. In figure 3, the number of deaths recorded for 1629 and 1630 has been compared with the “normal” mortality of previous years.¹⁰ All the points coloured from grey to black experienced a crisis: in the case of the black ones, a particularly great crisis with 10 times or more the normal mortality. The database for northern Italy has been complemented with 26 time series related to Tuscany.

Figure 3.

Increases in deaths in Northern Italy and Tuscany during the 1629–1630 plague.

None of the communities of the Po Plain comprised in the database, and in general none in Lombardy, Veneto, or Emilia Romagna, were spared a mortality crisis. The increase in deaths was particularly severe within a triangle placed at the intersection of these three regions. In this densely populated area, communication routes were excellent and trade flourishing, a fact that could have helped to spread the disease. From this central area, increases in deaths decline moving westwards and eastwards. Only in western Piedmont are communities to be found which were spared, or lightly affected, probably due to the morphology of the land. In this pre-Alpine area, full of rivers and steep hill ranges, particularly effective sanitary cordons could be established, improving the chances of controlling the contagion.¹¹ The control group, the Ligurian communities, confirms that the method employed is able to capture the occurrence of plague, given that the only communities experiencing a marked rise in deaths are placed in the territories of Rapallo and Finale, the only areas of the region infected in 1630. The same is true for Tuscany, as it is known that the southern part of the region, around the city of Siena, was largely spared by plague. The cluster of white dots in north Tuscany is related to Pistoia and its territory, which were only slightly affected. As in Piedmont, the morphology of this largely Apennine region might have helped to fight the spread of the disease. However, even in those Tuscan communities that were infected, increases in deaths proved lower than in northern Italy.

As in Rome, sanitary authorities might have helped to contain the contagion and the most recent literature has re-evaluated the effectiveness of their action, but it is difficult to see how this could fully account for such a marked difference from other areas whose health boards were equally efficient and well-trained.¹² Other factors that might have played a role are the delay with which Tuscany was struck by this plague wave compared with other parts of northern Italy,¹³ and the epidemic of typhus that ravaged much of the region in 1629 and decimated the poor, who were the preferred victims of early modern plague. Consequently, by 1630, typhus had already curtailed that part of the population particularly susceptible to catching and transmitting the plague, which could have resulted in lower overall mortality rates. However, the case of Tuscany remains, in Cipolla's words, “an epidemiological puzzle” (Cipolla 1981, p. 85).

The white dots in western Piedmont, Liguria, and southern and eastern Tuscany mark well the boundaries of the contagion. Within them, plague territorial pervasiveness was exceptionally high. The same is true for the second great epidemic (1656–1657), striking central and southern Italy. This plague happened largely outside the area covered by the database. Only Liguria is included and, as shown by figure 4, all of it, with the exception of Rapallo and Finale, was involved.

Figure 4.

Increases in deaths in Liguria during the 1656–1657 plague.

2.4 Probability of infection

The information presented graphically can be interpreted quantitatively. Out of ninety-seven communities¹⁴, only nine (9 per cent) were entirely spared by plague during the seventeenth century (table 4), and among them only one city: Biella in the north-west corner of Piedmont, a city well protected by natural barriers. Using the data to estimate probabilities of infection, in the year 1600, an urban community had a probability of just 0.05 (a 5 per cent chance) of being spared by plague throughout the century. Rural communities had a higher chance (P = 0.11), but basically these measures confirm the striking capacity of Italian plagues to spread to the countryside, especially considering that excluding Liguria the probability of being spared was only 0.05 for north Italian cities and 0.07 for rural communities—and this, for a single epidemic (1629–1630). The estimated probability would be 0.00, if not for a few places spared in western Piedmont.

Table 4.

Probability of infection of rural communities in different plague waves, 1600–1699

	1629–1630		1629–1630, Liguria excluded		1656–1657, only Liguria		1600–1699, North Italy
	Urban	Rural	Urban	Rural	Urban	Rural	Urban	Rural	Overall
Spared (n)	3	14	1	4	1	12	1	8	9
Infected (n)	19	61	18	50	2	9	21	67	88
Total	22	75	19	54	3	21	22	75	97
Probability of being spared	0.14	0.19	0.05	0.07	0.33	0.57	0.05	0.11	0.09

Source: database Alfani.

Focusing on the overall sample for 1600–1699 (P = 0.09), the 95 per cent confidence interval (t distribution) can be estimated as 0.04–0.15. In this period, the probability for any single north Italian community of being spared by plague was extremely low. This situation seems very different from other parts of Europe, particularly the North-West. A formal test would help in demonstrating this point, but we lack the data necessary to do this systematically. It is however possible to compare Italy with England by referring to data published by Slack (1985, p. 109). The point estimate of the probability of a parish in Devon or Exeter being spared from plague during 1565–1666 was 0.44. This is significantly different from the figure for northern Italy (P < 0.01).¹⁵ The fact that the period considered is shorter (1600–1657, since after 1657 plague disappeared from Italy) strengthens this finding.

Territorial pervasiveness and mortality rates of the 1656–1657 plague are similar to those found for that of 1629–1630. This is true for Liguria as well as for the infected areas of the Kingdom of Naples and the Papal State. Here, too, rural communities were struck as well as urban centres. Table 5 shows that the percentage of communities affected in most terre (rural districts) of the Kingdom of Naples was very high. For example, in the Principato Ultra and Principato Citra, it was 89.9 and 89.3 per cent, respectively. Territorial pervasiveness decreased in the terre farther from the capital (Naples). This is probably connected to lower urban density, relative scarcity of communication routes, and consequently, greater isolation of the communities. Institutions and sanitary authorities also played an important role in controlling the spread of the disease (Fusco 2007). On the whole, however, in the most densely populated areas, the territorial pervasiveness of this epidemic is comparable to that of 1630, as are the mortality rates in the countryside, sometimes exceeding 800 per thousand (Benedictow 1987 for Cilento; SIDES 1990 for Lazio, Apulia and Sardinia; Fusco 2007, p. 249 for rural mortality rates). A recent estimate places mortality at 430 per thousand in the whole Kingdom, much higher than earlier estimates of 200–300 per thousand (Fusco 2009). This may be too high, but it suggests a mortality of at least 300 per thousand, about equal to that found in northern Italy 25 years earlier.

Table 5.

Terre (“lands”) infected in the provinces of the Kingdom of Naples

Provinces	Percentage of terre infected	Total number of terre
Principato Ultra	89.9	158
Principato Citra	89.3	242
Terra di Lavoro	61.2	232
Contado di Molise	48.1	108
Capitanata	47.7	86
Basilicata	34.5	119
Abruzzo Citra	35.5	183
Abruzzo Ultra	30.0	223
Terra di Bari	26.9	52
Calabria Citra	16.4	171

Note: this table does not include the area surrounding Naples (thoroughly devastated), the provinces of Calabria Ultra (only three terre infected), and Terra d'Otranto (entirely spared).

Sources: my elaboration from data published by Fusco (2007).

2.5 Demographic consequences of high territorial pervasiveness

The fact that the countryside was depopulated similarly to the urban areas was a serious hindrance to recovery. When mortality is so high, as to prevent the local demographic forces from recovering by themselves, the only way to prevent a long-term population decline is immigration. This is what happened in northern Europe, serious and frequent waves of plague notwithstanding, and this was also the Italian experience during the sixteenth century (Alfani 2010a). In the seventeenth, though, the exceptional territorial pervasiveness of epidemics all but cancelled the demographic surplus of the countryside, destroying any chance of quick recovery.¹⁶ In Venice, where 46,500 perished in 1630 from a population of around 141,000, it took 70–80 years to fully recover. In Naples, where in 1656 about 150,000 died, the pre-plague level of around 300,000 inhabitants was recovered only in the late 1730s or early 1740s (Del Panta 1980, pp. 162–3, 168).

This slow recovery had primarily demographic reasons:

1. the epidemics covered an area so large and densely inhabited that it can be treated as a closed population. In other words, no relevant demographic help could come from the outside;

2. within this area, plague territorial pervasiveness meant the destruction of the potential for urban recovery by curbing the traditional demographic exchanges with the countryside;

3. the overall mortality rates were so high that a quick and generalized recovery would have been impossible even in the presence of significant migration influxes.

2.6 The disappearance of plague and the agent of the disease

The almost perfect territorial integration of the two main plague waves is an interesting phenomenon. While the areas spared in 1630 could attribute their favourable situation to effective sanitary cordons or to pure luck, in 1656 the territorial limits of the epidemic match too closely those of the earlier plague for this to be casual. While for central Italy, where the epidemic stopped in the middle of Abruzzo and spared Tuscany, sanitary authorities trained by the earlier wave could have played an important role, it is difficult to argue the same for Liguria, where the disease penetrated the boundaries of the Republic, sanitary cordons notwithstanding, and spared only the area around Rapallo (Finale was not under Genoese rule).

It is tempting to explain the territorial integration of the epidemics with the combination of two factors: 1. the exceptional territorial pervasiveness of seventeenth-century Italian plague, which could have provided widespread active immunization; 2. selection caused by extreme mortality rates and virulence. This draws the picture of a new strain of an old disease that kills too many people over too large areas in too short a time for its own good—thus laying the foundations for its own disappearance. Such a hypothesis differs from the traditional one, which implied mutual adaptation between humans and the plague pathogen (Hirst 1953; McNeill 1976), and which has failed to fully convince (Slack 1981). Spontaneous mutation of the pathogen could indeed have played a role, but a very different one, increasing and not reducing the damage done by pathogen to host.

Exceptionally high mortality rates and pervasiveness may not be enough to imply that new strains of plague were at work. However, if this implication is accepted, a further hypothesis can be proposed: that new, extremely dangerous strains of plague appeared somewhere in central or southern Europe in the early seventeenth century spread across the continent and favoured, in the medium term, the disappearance of endemic plague. Although further research is needed, one thing seems clear: the knowledge recently acquired about transformations over time of plague no longer allows thinking of it as a “uniform” disease.¹⁷ The possibility of different strains of plague competing over time and space must be given full consideration. This does not imply refuting all factors suggested by previous scholarship, but simply adding a player, and possibly a key one, in a complex game with many other participants.

This reconstruction has a weak point in its assumptions about immunization. Firstly, given the 25-year period separating the two Italian plague waves, this would be a very long-lasting, and consequently not very probable, mass immunization. Secondly, the possibility of human beings acquiring immunization from medieval and early modern plague is by no means certain, given that no lasting immunization can be acquired from Yersinia pestis, the agent responsible for the so-called third pandemic in the nineteenth century as well as for the most recent plague outbreaks (Manson-Bahr and Bell 1987, p. 591). Maybe we should focus on selection caused by widespread over-mortality as the main factor or on complex interaction of selection and immunization processes, but further interdisciplinary research is needed.

Something more needs to be said about the role of institutions and economic conditions. As already noted, the action of health authorities does not explain either why Tuscany was less affected than northern Italy in 1630, or why the 1656–1657 plague spared precisely the areas affected by the earlier epidemic. One could hypothesize that poor institutions are the reason why Italy was affected more severely than north-west Europe, but this hypothesis should be rejected because Italian anti-plague institutions were the best in the continent. The first permanent health boards were introduced in Italian cities during the fifteenth century and copied by Spain and France within few decades (Cipolla 1976). England, however, “was unlike many other European countries in having no public precautions against plague at all before 1518” and at the beginning of the seventeenth century was still intent on importing institutions that were common in Mediterranean Europe (Slack 1985, pp. 201–226). This is also the case for plague tracts, which in north-western Europe were mostly translations or strongly inspired by Italian or French originals, while in Italy we find, during the sixteenth century, an unparalleled boom in the publication of new works. Many of these included sections on “governing the plague,” a topic not covered by earlier tracts (Cohn 2009). While possibly in other areas of north-western Europe, for example the Low Countries, health institutions were similar to those in Italy, there is no reason to believe that they were better. The same is true for hygienic conditions and similar factors.

Regarding overall economic conditions, while Italy before the seventeenth-century epidemics was probably overpopulated as testified to by recurrent famines, it was still one of the wealthiest areas of Europe and had a solid economy (Sella 1997; Alfani 2013). Section 3 suggests that plague played a fundamental role in changing this situation, although by no means does this allow us to state that the high incidence of plague in Italy is explained by pre-epidemic economic conditions.

Overall, it seems that plague should be considered a mostly exogenous factor, also because at the beginning of the seventeenth century, it was probably no longer endemic in Italy. When plagues did occur in the peninsula, they were re-infections coming from other areas of Europe or the Mediterranean. We might even assume that Italian health institutions had been so successful as to drive the disease from the peninsula. When it came back, striking areas that in some cases had been plague-free for fifty years or more, it might have been favoured by finding a population the majority of whom had never been in contact with the plague pathogen.

3. Plague and the decline of Italy: hypotheses and research agenda

In seventeenth-century Italy, plague caused a demographic catastrophe that took many decades to recover. The long-lasting decline in population had demographic, and more specifically epidemic, reasons and was neither the consequence of economic difficulties nor of the malgoverno (bad government) of foreign dominators. Statements such as Helleiner's, “[Even without the plagues] the secular stagnation of the Italian economy in the period under review would probably have militated against demographic expansion,” betray the conviction that demographic decline was a consequence of economic decline (Helleiner 1967, p. 50).

The new data discussed here, combined with the most recent reconstruction of demographic trends in the century preceding the epidemics (Alfani 2013), suggest to reconsider this statement. Plague was the main cause of demographic decline in seventeenth-century Italy. More generally, by comparing the demographic trends of different areas of Western Europe (table 6) with plague incidence (table 2), there is clearly a strong inverse relation. Mortality, and not only economic or commercial growth, is a key factor explaining the changing demographic weight of different parts of the continent.

Table 6.

Demographic growth in Italy and Europe, 1600–1700 (millions of people)

	Italy: North	Italy: Centre	Italy: South	Italy: Isles	Spain	Germany	France	Netherlands	England and Wales
1600	6.5	2.2	3.3	1.5	6.8	16.2	18.5	1.5	4.5
1700	6.7	2.1	3.3	1.5	7.4	14.1	21.5	2.0	5.5
Change (%)	+3	−4.5	-	-	+9	−13	+16	+33	+22

Sources:Sonnino (1996) for Italy and Malanima (2009) for other European countries.

During the seventeenth century, only Germany performed worse than Italy, with a 13-per cent decline in population due at least as much to the Thirty Years' War as to plague. The Italian case is all the more striking because overall the great seventeenth-century wars affected it lightly. If northern Italy, struck by plague in 1629–1630, had recovered its lost population by 1680 or 1690, the centre and the south were still showing the signs of the 1656–1657 epidemic by 1700. This poor performance is not due to scarce demographic dynamism. After the epidemics, marriages and births peaked as normal after a severe mortality crisis, and population grew at a steady pace (in northern Italy after 1630, over 5 per thousand yearly). However, the lack of rural surplus population, coupled with the wide area covered by the plagues, prevented the kind of quick recovery that, in northern Europe, was being accomplished by means of steady population movements from countryside to cities. In England or the Netherlands, urban population was booming despite frequent plagues (table 7).

Table 7.

Urbanization rates in Italy and Europe, 1600–1700

	Italy: Centre–North	Italy: South	Spain	Germany	France	Netherlands	England and Wales
1600	14.4	14.9	11.4	4.1	5.9	24.3	5.8
1700	13.0	12.2	9	4.8	9.2	33.6	13.3
Change	−9.7%	−18.1%	−21.1%	+17.1%	+55.9%	+38.3%	+129.3%

Note: rates refer to cities with more than 10,000 inhabitants.

Sources:Malanima (2005, p. 106) for North Italy; De Vries (1984, p. 39) for other areas.

Plagues played a key role in reducing Italian urbanization rates. Apart from eliminating a large share of the population, they acted as a “system shock” for Italian economies, precipitating a mainly urban crisis that resulted in a long-term decline in urbanization rates (Alfani 2010a).¹⁸ While this article does not aim to analyse in detail the economic consequences of the Italian epidemics, some points need to be made. From a macro perspective, the sharp decline in population favoured the decline in power and international influence of the Italian states. This process had been underway since the Italian Wars (1494–1559) and also had political and institutional reasons (Alfani 2013). However, only during the seventeenth century did those Italian states not under “foreign” rule lose most of their residual capacity for autonomous military action, in its turn increasingly dependent on the fiscal capacity of the State (Bonney1999; Pezzolo 2012). The epidemics, by curbing total product, also reduced the possibility of the Italian states to compete in the European power struggles. The rise of Piedmont, ruled by the House of Savoy, as the main military power in Italy may be linked to the fact that it was the northern Italian state that suffered less from the plague.

Loss of military and diplomatic power was not without consequence for the conditions of international trade. It has been suggested that easy access to the Atlantic routes and the institutions created (in non-absolutist countries) to exploit the opportunities offered by the New World fuelled the First Great Divergence (Acemoglu et al. 2005). Epidemiological factors strengthened this process and, in the case of leading Mediterranean areas such as Italy, hindered any residual possibility of profiting from an increase in world trade. Given that plague struck in a lighter way those countries credited with developing the best institutions, it is possible that part of the impact on long-term growth attributed by some to institutions is actually due to epidemiological factors.

The decline in total product has been often used to suggest that the seventeenth-century epidemics caused serious damage to the Italian economies. In the case of a fundamental sector, the wool industry, in most northern Italian cities, the levels of production following the 1630 plague were far from those of the beginning of the century. In Lombardy, the production of woollen cloths had declined from an yearly average of 15,000 to ∼3,000 in 1640 in Milan and from 8–10,000 to ∼400 in 1650 in Como; in Cremona the 187 members of the Arte della Lana to be counted in 1615 had shrunk to 23 by 1648; in Monza the 20 wool enterprises present in the city in 1620 had entirely disappeared by 1640 (Cipolla 1959, pp. 605–607; Sella 1959, p. 547). In Veneto, the plague fostered the complete disappearance of the production of woollen cloths in Verona and caused lasting damage to that of Treviso and Bassano (Panciera 1996, pp. 15, 22). When information is scattered in time, it is difficult to distinguish the specific impact of the plague on a sector that was facing increasing international competition. However, when we can measure yearly production (figure 5), we find that not only did production greatly decrease in the plague years, but after the crisis the recovery was difficult, slow and overall the production trend seems to have moved to a definitely lower level.

Figure 5.

Yearly production of wool and linen cloths in Venice and Florence, 1620–1645 (indexes; value 100 equals to average yearly production in 1620–1628). Sources: Panciera (1996, pp. 42–43) for Venice; Romano (1952, pp. 511–512) for Florence.

Plague affected also other sectors, such as linen (figure 5) and silk. In Milan, the production of silk drapes fell by ∼80 per cent from 1606 to 1636, while in Venice this sector, flourishing in pre-plague years, had to face its first crisis ever (Cipolla 1959, p. 606; Panciera 2006, p. 191). Generally, the damage suffered by silk production was not long-lasting, but the example of Milan reinforces the idea that at the local level plague proved able to determine a deep structural crisis and a displacement effect for entire sectors, and not only the textile industry. In Milan, also the building sector suffered greatly, as in 1656 the Collegio degli Ingegneri ed Architetti reported that house values were still 25 per cent lower compared with pre-plague years (Sella 2010, p. 127). Similarly, a lasting decline of house rents, in the 25–35 per cent range, followed the epidemic (Barbot 2008, pp. 142–151).

Traditional historiography also mentioned a rise in wages, due to the scarcity of workforce, as a negative consequence of the plague. This would have made Italian products less appealing on the European markets at a time when international competition was on the rise, contributing to explain the difficult recovery of many industries (Cipolla 1993, pp. 248–249). However, an increase in wages is not per se detrimental to the economy. More generally, the idea that plague was damaging to the economy has been challenged on the grounds that what should be considered is per-capita, and not total, product. In this view, the standards of living of the survivors improved so that plague might have proved beneficial in the medium–long term (Malanima 2002, p. 345; Malanima and Capasso 2007, p. 29). This is a strong argument, which is widespread in recent historiography about the economic consequences of epidemics in Europe (Clark 2007, pp. 99–102; Pamuk 2007; Voigtländer and Voth 2012). Indeed, the great Italian epidemics of the seventeenth century helped to balance population and resources (Alfani 2010a, b, 2013). However, there is still much to say about the macro-economic consequences of these demographic catastrophes. All factors considered, it seems probable that the seventeenth-century plagues were detrimental to the Italian economies. Some lines for future enquiry can be mentioned.

First and foremost, the fact that plague did not strike all of Europe in the same way implies that any evaluation of the impact of the disease across the continent should take into account as much the absolute damage, as the relative. The fact that the Italian populations took 70–80 years to recover would not be so relevant, if other parts of Europe, in the meantime, had not moved on. Furthermore, in an age of mercantilism, internal aggregate demand could have been of key importance in preventing Italian manufactures from reaching the volume of product necessary to compete effectively, both abroad and—later—in domestic markets. By curbing aggregate demand, the plagues could have determined a decline in production levels that would prove impossible to restore even after demographic recovery. This is because the epidemics struck at the worst possible moment: Italian economies were forced to slow down while others accelerated. In the short- and medium-term, the increase in per-capita resources might well have prevented a decline in economic welfare, but in the long term, Italy was forced on a path which led it to become, by the eighteenth century, an economic backwater.

A third point is the damage done to human capital. While early modern European plague was mainly a disease of the poor and unskilled (then, replaceable), mortality rates of the order of 300–500 per thousand could not be reached without the disease becoming again, at least to a degree, a universal killer. Many studies suggest a shortage of skills in post-plague Italian economies, a fact that further differentiates the seventeenth from the sixteenth century plagues (Pullan 1964; Andreozzi 2010; Alfani 2013). More generally, even if pre-industrial societies could easily mend after a mortality crisis, the possible existence of thresholds should be recognized which, when surpassed, made it difficult to provide effective answers.

4. Conclusions

The data presented here have shown that plague affected unevenly seventeenth-century Europe. The use of a new database has made it possible to postulate that Italian plagues had dire consequences, because of their extreme mortality rates and territorial pervasiveness. The latter variable has been shown to be key in determining both the dimension of the demographic damage caused by plague, and the severity of its consequences. When plague proved able to spread pervasively to the countryside as well as to the cities, the possibility of a quick recovery of the urban populations was curtailed. The article also suggested that plague greatly contributed to the relative economic decline of Italy and set an agenda for investigating fully the economic consequences of the epidemics.

As a final remark, this study of seventeenth-century plagues has much to offer also to scholarship focused on earlier periods. One lesson from the early modern age is that one should be wary of considering plague a “great equalizer.” Instead, it distributed around Europe advantages and disadvantages, conditioning the demographic, political-institutional, and economic performance of different regions in ways which are still largely unknown.

Acknowledgements

I thank Maristella Botticini, Bruce Campbell, Gregory Clark, Samuel K. Cohn, Paolo Malanima, Richard Smith, Hans-Joachim Voth, seminar participants at Bocconi University, Centre Roland Mousnier—Université Sorbonne, University of Florence, INED, as well as participants at the 2010 Economic History Society Annual Conference and the 2012 European Population Conference for helpful comments. I am very grateful to Lorenzo Del Panta for providing the time series of burials for Tuscany, to Alessio Fornasin and Claudio Lorenzini for providing some of the time series for Friuli, to Matteo Di Tullio for helping to collect the time series for the area around Finale, and to Vicente Pérez Moreda and Ronald Rommes for supplying crucial information about plague in Spain and the Dutch Republic, respectively. This article was partly written during my stay at the Cambridge Group for the History of Population and Social Structure, which proved an excellent and friendly research environment. I am grateful to the Wellcome Trust for generously funding my stay in Cambridge.

1

About these debates, which involved the agent responsible for the disease, Cohn (2002); Theilmann and Cate (2007); Alfani and Cohn (2007); Cohn and Alfani (2007); Duncan and Scott (2001); Haensch et al. (2010).

2

About the demographic and economic consequences of the Black Death, Cohn (2007); Pamuk (2007).

3

A more conservative estimate for Central Italy would be in the range of 25–30 per cent, considering that Tuscany was touched relatively lightly by the 1630 epidemic.

4

Slack (1985, p. 174) estimated plague victims for England in 1570–1670 at around 658,000. An estimate for 1600–1670 has been derived hypothesising constant distribution of plague victims over time. For northern Italy, an overall mortality rate of around 30–35 per cent has been applied to a population of 6.5 million people.

5

Amsterdam for example was struck by plague in 1602, 1617, 1623–1625, 1635–1637, 1654–1655, and 1663–1664. Duncan and Scott (2001, p. 331); Van Bath (1965). About Flanders and Hainaut, Van Werveke (1965); Arnould (1965).

6

Another severe plague had devastated Castille and Andalusia in 1599. About this, Bennassar (1969); Vincent (1976). This epidemic alone killed 9 per cent of the Spanish population. Perez Moreda (1980, p. 280).

7

About completeness tests, Wrigley and Schofield (1981, pp. 19–23). Here all time series were rejected in which information for 1630 was lacking or severely incomplete and/or information for more than two of the five years 1624–28 was missing/incomplete (the second period was needed to estimate the ‘normal’ level of deaths before the plague). Similarly for the 1656–57 plague. Some time series have been accepted only for one of these two epidemics.

8

The complete dataset is available here: http://didattica.unibocconi.eu/Alfani_database.

9

The best-known case is probably Eyam in England (370–460 per thousand in 1665–1666). Bradley (1977).

10

The ‘normal’ level of deaths has been defined as the average for the five-year period, 1624–1628, maximum and minimum value excluded. This has been compared to the maximum reached between 1629 and 1630 (some early victims of the epidemic register a peak in 1629). For Tuscany, only 1630 has been considered.

11

About the plague of 1630 in Piedmont, Alfani (2010c).

12

About Tuscan sanitary authorities during the 1630 epidemic, Cipolla (1981); Henderson (2001). More generally, about medical thought and action against the plague, see Cohn (2009). About the re-evaluation of the effectiveness of sanitary authorities, Del Panta (2007), Fosi (2006).

13

As suggested by Cipolla (1981, p. 84), but neither he nor I find it entirely satisfying – given that cities in Tuscany struck at the same time showed very different plague mortalities. On seasonality of plague, Alfani and Cohn (2007).

14

Four were discarded due to incomplete data.

15

Null hypothesis = same probability of infection in the two areas. Slack identified the occurrence of plague locally as doubling of burials over the normal trend. The same definition was applied to the Italian data for the purpose of the test.

16

Many case studies demonstrate that in contemporary northern Europe, immigration from the spared countryside was essential in permitting urban growth notwithstanding the frequency of epidemics. For England, see Doolittle (1975, p. 340–341). For Holland, Helleiner (1967, p. 47).

17

Cohn (2002); Alfani (2013); for a bio-genetic reconstruction of the evolution of different strains of Yersinia Pestis, Haensch et al. (2010); Morelli et al. (2010).

18

On the impact of plague on Italian urbanization rates also see Bosker et al. (2008, pp. 101–103).