Available in paperback for the first time, this work of original scholarship is the first to trace in full detail how the UK's system for defining parliamentary constituencies has evolved since the Great Reform Act of 1832 and how the eight redistrictings since then were undertaken. Particular attention is paid to the five redistrictings that have been undertaken by the independent Boundary Commissions established in 1944, with a detailed study of all aspects of their work on the most recent review of all constituencies. The book is both a standard reference work on redistribution in the UK and provides the only detailed insight into how that task is currently undertaken, based on a study of the relevant documents and interviews with over a hundred of those most closely involved. The book will be essential for all those interested in the British constitution, and administrators concerned with making the constitution successful, as well as politicians.