For seven decades the History of Parliament Trust has overseen the publication of the official history of the House of Commons. The published volumes cumulatively form a unique historical resource. The membership of no other legislative assembly has ever been studied in such detail. Publication of the 1640–1660 House of Commons volumes, which will fill one of the few remaining gaps in that sequence, is no longer a distant prospect. This book is one of a number of spin-offs arising indirectly from that main project. My primary debt is therefore to the trustees of the History of Parliament Trust, its Editorial Board and the Director, Paul Seaward, for permission to use material from the forthcoming 1640–1660 volumes. The present book ought be viewed, first and foremost, as a prolegomenon to the constituency article on Cambridge borough which will in due course appear in that work.

What follows has moreover been written very much within that History of Parliament tradition. It might even be thought distinctly ‘Namerite’. Underpinning it is the assumption that no MP should be seen in isolation. The men who sat in the early-modern House of Commons were shaped by the lives they had led before they got to Westminster and the elections which had brought them there each had their own particular peculiarities. Those backgrounds might be conventional, unremarkable or unedifying. But together they all helped make the politics of this period what it was.