This book, first published in 1990, examines the origins and evolution of the security police, considering the continuities as well as changes in its function as guardian of the regime’s security. It analyses the KGB’s involvement in Kremlin politics, the structure and organisation of the KGB, its formal tasks and legal prerogatives as set forth by the Party leadership, and the actual functions it performs on behalf of the Soviet regime. Underlying this analysis is an attempt to assess the power and authority of the KGB relative to other political institutions and to explain the crucial dynamics of the Party- KGB relationship.