Sheikh Fakhr ad-Din, in Kurmanji Fexredîn, is one of the seven Holy Beings of the Yezidi Heptad and the personification of the Moon, forming a complementary pair with his brother Şêşims, who personifies the Sun. On the earthly plane he is counted among the four sons of the prince Êzdîna Mîr who make up the group of the Four Mysteries, and he is especially revered as a composer of sacred poetry: Yezidi religious authorities credit him with the authorship of many thousands of qewls, beyts and qesîdes, of which only a small fraction is said to survive the centuries of persecution. He is remembered as having had several sons who themselves became important Yezidi saints, and his name remains among the most frequently invoked in the community's liturgy.