Ögedei, (also Ögädäi, Ögedäi, etc.), was the third son of Genghis Khan. He succeeded his father to rule as the second khan of the Mongol Empire. He continued the expansion the empire that his father had begun. Like all of Genghis' primary sons, he participated extensively in conquests in Northern China and Central Asia.

He was elected supreme khan in 1229, according to the kuriltai held after Genghis' death, although this was never really in doubt as it was Genghis' clear wish that he be succeeded by Ögedei.

During his reign, the Mongols completed the destruction of the Jurchen Jin empire (in 1234), coming into contact and conflict with the Southern Song. In 1235, under the khan's direct generalship, the Mongols began a war of conquest that would not end for forty-five years, and would result in the complete annexation of all of China. Mongol armies vassalized Korea, established permanent control of Persia proper (commanded by Chormagan) and, most notably, expanded westwards under the command of Batu Khan to subdue the Russian steppe. Their western conquests included almost all of Russia (save Novgorod, which became a vassal), Hungary, and Poland.

The Mongol expansion throughout the Asian continent under the leadership of Ögedei helped bring political stability and re-establish the Silk Road, the primary trading route between East and West.

Ögedei's death in 1241, brought the Mongol invasion of Europe to a premature end. The commanders heard the news as they were advancing on Vienna, and withdrew for the kuriltai in Mongolia, never again to return so far west.

His son Güyük eventually succeeded him after the five-year regency of his widow Töregene Khatun.