Mongol Empire. Great Khans: Ögedei b. Chingiz khan. AH 624-639 / AD 1227-1241. AR Silver Dirham (2.82 g). Rev: in persian (be-qovvat-e aferidighar-e ‘Alam) By the Power of the Creator of the World, in three lines / Obv: Citing the Abbasid caliph al-Mustansir (AH 623-640). Album 1978K. F-VF. Ögedei Khan (1186–1241 AD) was second khagan-emperor of the Mongol Empire. The son of Genghis Khan, he continued the expansion of the empire that his father had begun. Born in 1186 AD, Ogedei fought in numerous battles during his father's rise to power. After being granted a large appanage and taking several wives, including Töregene, he played a prominent role in the Mongol invasion of the Khwarazmian Empire.