When John Pocock published Politics, Language and Time in 1971, he opened his Introduction by remarking that ‘during the last ten years scholars interested in the study of systems of political thought have had the experience of living through radical changes, which may amount to a transformation, in their discipline’. If it now seems clear that the 1960s did indeed witness the beginning of a revolution in our ways of thinking about the history of political theory, it is even clearer that John Pocock himself was one of the most active and important of the revolutionaries. We who have written the following collection of essays in his honour are all happy to acknowledge his inspiration and influence. We have profited from his insistence that the history of political theory should be written as a history of discourse, and we have sought at the same time to address ourselves to some of the specific questions he has raised about the evolution of early modern British political thought. We hope that the resulting volume will be read in the spirit in which we conceived it, as an affectionate and wholehearted tribute to a generous historian whose wide erudition, magisterial prose and insatiable curiosity about the mental world of Anglo-Saxon politics continue to generate a remarkable corpus of historical writing, one still capable of releasing those frissons historiques which we expect only from the finest of historians.