Based in Iraq, Syria and Turkey, the Yezidi people claim their religion - a unique combination of Christian, Islamic, and historical faiths - to be the oldest in the world. Yezidi identity centres on their religion, Sharfadin, which has evolved into a highly complex pantheon of one God with many incarnations, the chief of whom is Melek Taus, the Peacock Angel. The Yezidi faith can be traced to a range of pre-Islamic belief systems, such as Sufism, some extreme Shi'ite sects, Gnosticism and other traditions surviving from the ancient world. This particular formulation has served to unify Yezidi religious identity and ethnicity. Based on extensive fieldwork, The Religion of the Peacock Angel presents the first detailed examination of the Yezidi pantheon. The idea of one God and his chief incarnations is first analysed, then the various 'deity figures,' saints, holy patrons and divinized personalities in the Yezidi belief system are considered in the context of related religious traditions. The study determines the place of all these characters in the system of the Yezidi faith, defining their main functions, features, and genealogies.