This introduction explores the relationship between intellectual, political and religious history, and how they should fruitfully be integrated with classic parliamentary history. It argues that the early modern parliament must be understood through broader developments in historical thought and practice. The first part of the introduction examines the changing and unchanging character of history in this period, which provides the context for the essays in the volume. Thereafter the introduction relates approaches to the past to the growing historical consciousness within and about parliament and the historicised modes through which early modern authors chose to think and write about it. These new perspectives are analysed in the context of the historiography of parliament of the past century. It is argued that the constitutionalist mode of thinking so dominant at the end of our period grew out of the interaction of history, law and politics in, around and about parliament. The collection thus restates the crucial role of institutions for the study of political culture and thought.