Protestant apologetics had to counter the challenge of Catholic writers that their churches lacked proper historical foundations. In England the second generation of reformers, in particular, sought to establish the legitimacy of their Church partly by a return to origins, to the earliest periods of conversion, and to appropriate the foundation stories for their own faith. Their debates with Catholic authors ranged over the period from the supposed establishment of Christian mission to the coming of St Augustine. However, they spent much energy on the specific problem of King Lucius, supposedly ruler over Britain at the end of the second century. Lucius had asked for missionaries from Rome, said Bede, and had established the faith with bishoprics and archbishoprics, said Geoffrey of Monmouth. In the thirteenth century Geoffrey's story was enhanced with a forged letter from the pope, Eleutherius, who was supposed to have sent missionaries. Various aspects of this story proved attractive to one or other side – the Catholics claiming Lucius as evidence of early conversion and Rome's role in it, the Protestants using it to support the idea of a national church, early episcopacy and God's providential concern for the English. Although questions about Lucius's historicity were raised from the later sixteenth century onwards, he proved far too useful to both sides to be abandoned during the long Reformation.