Before his death, Genghis Khan selected his third-born son, Ögedei, to succeed him. Ögedei was described by contemporaries as a hard-drinking, harsh man of great passions. Two years passed between his father's death and his confirmation as great khan by the Mongol nobles. Ögedei expanded the empire and shifted its policies toward conquered lands, but his drinking caught up with him. He died in 1241.
After Ögedei, heirs to Genghis Khan's throne would regularly find their legitimacy contested. His son, Güyük, was elected great khan over Batu, the man who would have struck into western Europe in Ögedei's name had he not died (and was also Genghis Khan's grandson by his eldest son). Güyük died before the tension could create lasting damage to the empire, but the matter of his successor kept the Ögedei and Batu branches of the family in bitter contest. Sorqoqtani Beki, Batu's aunt, outmaneuvered the opposition and clinched the throne for her son Möngke. Under him, the Mongols took Baghdad and established territory on the Mediterranean. They also purged his family rivals.
When Möngke died, the next great khan seemed likely to be either Arigböge and his brother Kublai, sons of Genghis Khan's youngest son. The brothers fought a four-year civil war for the throne, ending with Kublai's victory in 1264. But he was never elected by a council of nobles, which left his position somewhat suspect among the Mongols even after he became great khan.
