Tolui (also rendered Toluy, c. 1190–1232) was the youngest son of Genghis Khan by Börte. His ulus, or territorial inheritance, at his father's death in 1227 was the homelands in Mongolia, and it was he who served as civil administrator in the time it took to confirm Ögedei as second khan. Before that, he had served with distinction in the campaigns against the Jin Dynasty and the Khwarezmid Empire, where he was instrumental in the capture and massacre at Merv.

When Genghis Khan was deciding who should succeed him he had trouble choosing between Tolui and Ögodei. Tolui had amazing military skills and was very successful as a general, but Genghis Khan chose Ögodei because Ögodei was more capable politically. Genghis Khan felt that Tolui would be too cautious to be an effective leader.

After Genghis Khan's death, Mongol nobles gathered together and elected Tolui as the new Khan, but Tolui rejected their decision and gave the Khanate to his brother, Ögodei, fulfilling his father's wishes. The Mongol nobles' moves were partly influenced by the tradition that the youngest son inherits his father's properties and partly because Tolui had the largest and most powerful army at the time.

Perhaps more important is the role his family, the Toluids, had in shaping the destinies of the Mongol Empire. Through his wife Sorghaghtani Beki, Tolui fathered Möngke, Kubilai, Ariq Boke, and Hulagu, and thus was the progenitor of the last of the great Khans, the Yuan Dynasty of China, and of the Il Khans.

Rivalry between the Toluids and the sons of Ögedei and Jochi caused stagnation and infighting during the regency periods after the deaths of Ögedei and his son Güyük.

However, it was a rivalry from among Tolui's own sons, Kubilai and Ariq Boke, that fragmented the power of the empire and set the western khanates against each other in the early 1260s.

1190 births | 1232 deaths | Mongol Khans

Tolui Khan | تولی | Tolui | טולוי | Tolui | トルイ | Tołuj | Tolui-kaani | Đà Lôi | 拖雷