As recorded by Rashid-al-Din in his Jami al-Tawarikh, 4 September 1236 was the date on which the sons of Jochi - Batu, Orda, and Berke, Ugedei’s son Kadan, Chagatai’s grandson Büri, and Jenghiz Khan’s son Kulkan declared war on the Mokshas, Burtas and Erzyas.
Mokshas |
The ethnic identiry of the Burtas is disputed, with several different theories ranging from them being a Uralic tribal confederacy (probably later assimilated to Turkic language), and therefore perhaps the ancestors of the modern Moksha people, or that they were an Aryan tribe, possibly the ancestors of the modern Mishars, and/or Volga Tatars and Chuvash.