This volume of Encyclopaedia Islamica is the fourth of a projected 16-volume publication, consisting of an abridged and edited translation of the Persian Da'irat al-Ma'arif-i Buzurg-i Islami, one of the most comprehensive sources on Islam and the Muslim world. One unique feature of this work of reference lies in the attention it gives to Shi'i Islam and its rich and diverse heritage, which makes it complementary to other encyclopaedias. In addition to providing entries on important themes, subjects and personages in Islam generally, it offers the western reader an opportunity to appreciate the various dimensions of Shi'i Islam, the Persian contribution to Islamic civilisation, and the spiritual dimensions of the Islamic tradition.