From infallible Imams to Ayatollahs in Iran, Shi'ism has long been a prominent, if misunderstood, branch of Islam. It regards Ali, Muhammad's son-in-law, as the Prophet's legitimate successor. But theological differences between the Shi'ah and Sunni Muslims have led to sectarian violence, massacres and the desecration of holy sites. In this Beginner's Guide, Dr Moojan Momen offers an accessible and comprehensive overview of Shi'ism,...