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. Temüjin 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.