the town and massacring its inhabitants (1221). 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 for a "kurultai", a political and military council - a formal meeting used both in familial matters and in matters of state. Genghis Khan had won election/appointment as Khan of his tribe during a kurultai, and he called them often during his early campaigns to garner public support for his wars – such meetings were key to Genghis Khan's 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, Chagatai raised the issue of Jochi's legitimacy. 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. Succession controversy During the autumn of 1223 Genghis Khan started for Mongolia after completing the Khwarezm campaign. Ögedei, Chagatai and Tolui went with him but Jochi withdrew to his territories north of Aral and Caspian Seas. There he remained until his death and would not see his father again in his lifetime. 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