Heinz Halm's work presents a thorough and accessible discussion of the history, theology, and current state of this branch of Islam. Newly revised, Shi'ism includes updated information on the fate of the Shi'ite revolution in Iran as well as a new chapter on Iraq. Observing a tradition more than 1000 years old, Shi'ites represent 10 percent of the Muslim population, or 100 million people. Halm explores how Shi'ism differs from the rest of Islam, discussing the prominence of its authorities, the Imams, as well as its legal system, practices of worship, places of pilgrimages, and a religious ethos characterized by a fervor to suffer for the cause. Additionally, Halm provides a lucid survey of the various branches of Shi'ism, paying attention to their historical, organizational, and theological developments. The book also considers the appeal and impact of Imams in contemporary Shi'ism and their interpretation of the social and economic problems gripping the Islamic world.