Based on the work of the ESRC Modern Archives Unit at the London School of Economics, this is an indispensable reference work for librarians, historians and social scientists seeking information on the archive sources for British history, politics and society since 1945. Over 600 institutions are listed, with explanatory introductions and notes on the nature and whereabouts of their archive material. They range from the major political parties and national organisations like the TUC and the CBI to pressure groups in areas as diverse as nuclear disarmament, European unification and the women's movement. The result is not only a major work of reference but also a 'vade mecum' for the working historian and research student.