Genghis Khan had divided his empire into khanates among his four surviving sons during his lifetime. Jochi was entrusted with the westernmost part of the empire, then lying between Ural (Jaiq, Djaik, Iaik, Jaiakh) and Irtysh rivers. In the Kurultai of 1229 following Genghis Khan's death, this partition was formalized and Jochi's family (Jochi himself had died six months before Genghis Khan) was allocated the lands in the west up to 'as far as the hooves of Mongol horses had trodden'. Following the Mongol custom, Genghis Khan bequeathed only four thousand 'original' Mongol troops to each of his three elder sons and 101,000 to Tolui, his youngest son. Consequently, Jochi's descendants extended their empire mostly with the help of auxiliary troops from the subjugated populations which happened to be Turkic. This was the chief reason why the Golden Horde acquired a Turkic identity. Jochi's inheritance was divided among his sons. His sons Orda and Batu founded the White Horde and the Blue Horde, respectively, and would later combine their territories into the Kipchak Khanate or Golden Horde. Another of Jochi's sons, Shiban, received territories that lay north of Batu and Orda's Ülüs.