Book excerpt: A Guide to the Papers of British Cabinet Ministers 1900-1964 is the revised and expanded edition of a volume first published by The Royal Historical Society in 1974. Its aim is to provide up-to-date information on the papers of 323 ministers in the first edition and include all Cabinet ministers (or those who held positions included in a Cabinet) until the resignation of Sir Alec Douglas-Home as Prime Minister in 1964. Thus the scope of this edition has increased from the 323 ministers in the first Guide to 384, and therefore incorporates those who held relevant positions in the Churchill, Eden, Macmillan and Home governments. Information is provided on 60 'new' ministers and the previously omitted Lord Stanley. This Guide therefore is a major research tool and a source of information on personal papers, often in private hands, of people who played major roles in twentieth-century political life.