The Cambridge School of the history of political thought exists as a tradition of teaching in the History Faculty of Cambridge University, and as a set of works including famous books such as The Political Thought of John Locke, The Machiavellian Moment and The Foundations of Modern Political Thought. It acquired its distinctive status because of three methodological articles written in the 1960s by the triumvirate of J.G.A. Pocock, John Dunn and Quentin Skinner. These articles are usually assimilated to each other. No doubt there was much consonance between the three articles. But I demonstrate through a close reading of the three articles that each author placed a very different emphasis on the status and purpose of the history of political thought, and that the differences between the articles help to explain the remarkable differences in the subsequent writings of the authors from the late 1960s onwards. This article is not part of the recent tendency to study the thought of the last fifty years historically, though it may of course be a preliminary to that. My concern is textual, not contextual. This article should interest anyone concerned with the question of the relevance of historiography, the history of ideas and the history of political thought to the study of politics.