The differences in tactics between Jochi and Chagatai in early 1221 added to their personal quarrel about the succession. To settle the matter, Genghis Khan called a kurultai. The formal meeting was used in both familial matters and matters of state. Temüjin was elected/appointed Khan of his tribe during a kurultai, and he called for them often during his early campaigns to garner public support for his wars. These meetings were key to Genghis Khan legitimacy. Tribal tradition was also critical. As Genghis Khan's first born son, Jochi, was favored to rule the clan and the empire after his father died. At the familial kurultai called in 1222, the issue of Jochi's legitimacy was brought up by Chagatai. At that meeting, Genghis Khan made it clear that Jochi was his legitimate first born son. However, he worried that the quarrelsome nature of the two would split the empire. By early 1223 Genghis Khan had selected Ögedei, his third son, as his successor. For the sake of preserving the Empire, both Jochi and Chagatai agreed but the rift between them never healed. Their rift would later politically divide the European part of the Mongol Empire from its Asian part permanently.
Though the histories are unclear, there is evidence that Jochi conspired against Genghis, and that Genghis in return pondered a pre-emptive strike. When Genghis Khan returned home he sent for Jochi. When the latter refused to obey Genghis Khan sent Chagatai and Ögedei against him. But before it came to open hostilities, news came that Jochi had died in February 1227.
Genghis Khan had divided his empire among his four surviving sons during his lifetime. Jochi was entrusted with the westernmost part of the empire, then lying between Ural and Irtish 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 Turkish. This was the chief reason why Golden Horde acquired a Turkish 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.
Genghis Khan had made Jochi responsible for the supervision and conduct of the community hunt. Hunting was essentially a large scale military exercise designed specifically for the training of the army. It frequently encompassed thousands of square kilometers of area, required the participation of several tumens and lasted anywhere between one to three months. Rules and procedure of the conduct of the military exercise were encoded in the Yassa.
Certain incidences hint towards the fact that Jochi was of a kinder disposition than Genghis Khan, though the adjective “kind” must be interpreted by the standards of his times and milieu because Jochi had had his share of indulgence in massacres of civilians. On one occasion Jochi pleaded with Genghis Khan to spare the life of a son of an enemy chief who had been taken captive and who happened to be a great archer. Jochi argued that such a great archer can be an asset to the Mongol army. Genghis khan brushed aside this argument and had the captive executed.