High Quality Content by WIKIPEDIA articles! The Kereit (Mongolian: Хэрэйд; Kazakh: Керей) tribe was one of the five major tribal confederations (khanlig) in Mongolian plateau in the 12th century, and dominant in the area and, as allies of Genghis Khan, influential in the rise of the Mongol Empire. Converted to Nestorian Christianity in the 11th century, they were also a key example of prominent Christians among the Mongols.