This article offers a reappraisal of the performance of Iain Duncan Smith as Conservative Party leader between 2001 and 2003. The rationale for the paper stems from the relative neglect of his leadership by political scientists. The paper argues that to disregard his party leadership tenure is to fail to understand the evolution of Conservative Party politics in the era of New Labour hegemony. Utilising a range of interviews with significant Conservative elites from the era of opposition, Duncan Smith's acquisition of the party leadership and brutal removal from it are reassessed. More significantly, the paper argues that his limitations as a political leader and his poor party management style should not mask the fact that the processes of policy renewal and strategic reorientation initiated under his leadership were important precursors to David Cameron's capacity to push forward his modernisation agenda post-2005.