 In a charter of Béla IV, a Cuman chieftain "Zayhan" or "Seyhan" is mentioned, assumed to have been Köten.An Arabic source calls his people Kipchaks; "Kutan" is mentioned as belonging to the "Durut" tribe of the Kipchaks.According to Pritsak, "Durut" was the Terter tribe of the Cumans.