Jami' al-tawarikh
According to the early 14th-century work "Jami' al-tawarikh" by Rashid-al-Din Hamadani, Mongol legend traced the clan back to eight brothers with unusually dark faces and the confederation they founded. "Kerait" was the name of the leading brother's clan, while the clans of his brothers are recorded as "Jirkin, Konkant, Sakait, Tumaut, Albat".