A new edition of Heinz Halm's comprehensive survey of all the Shi'ite groups. It traces the development of all the individual branches from their common origins to their current status in the modern world. The dogmatic and organisational development of each of the various branches of Shi'ism is discussed and is placed in the context of their particular history. Special attention is given to the emergence of the Imamite 'clergy' and the social and political role which has enabled them to establish a revolutionary regime in Iran, and each chapter contains an invaluable bibliography giving easy access to other books and original sources in translation. Key Features: * each branch of Shi'ism placed in its own historical context * bibliographies at the end of each chapter divided into primary and secondary sources * includes chapters on all varieties of Shi'ism * New edition contains new material on the Shi'a in Iraq and on the Iranian Revolution, and up-dated bibliographies