Ogedei Khan (c. 1186 - December 11, 1241) was the third son of Genghis Khan and second Great Khan (Khagan) of the Mongol Empire by succeeding his father. He continued the expansion of the empire that his father had begun, and was a world figure when the Mongol Empire reached its farthest extent west and south during the invasions of Europe and Asia. Like all of Genghis' primary sons, he participated extensively in conquests in China, Iran and Central Asia. After the death of Genghis Khan, his youngest son Tolui acted as the temporary head of state affairs until in 1228, yellow cattle year, the third son of Genghis Khan, Ogedei was enthroned by the Great Assemblage held in Hudeearal on the river Herlen. Ogedei was born in 1187,the red horse year, and from the age of 17 he began to contribute to the strenghening of state affairs. Ogedei Khan improved the organizational form of the state, finished the construction of Karakorum city begun by his father Genghis Khan and made it the capital of the Mongolian Empire. Ogedei Khan passed away in 1241, the white cattle year, at the age of 56.