Tolui acted as regent after Genghis Khan’s death in 1227. As the youngest son, he administered the Mongol Empire during the interval before his older brother Ögedei was formally chosen as Great Khan in 1229.
Mongol succession was not governed by a simple automatic rule. The empire’s leading princes and commanders had to recognize a successor at a kurultai, a major political assembly. Tolui was a serious candidate because he was an accomplished commander and controlled the Mongolian heartland, but Genghis had selected Ögedei as his preferred successor. Tolui therefore governed temporarily rather than inheriting the supreme title.
His regency included overseeing mourning, maintaining imperial administration and arranging the succession process. He ultimately supported Ögedei, who became khan in 1229. Tolui later died in 1232 under uncertain circumstances, but his family became immensely influential: his sons Möngke and Kublai both became Great Khans, while Hülegü founded the Ilkhanate in Persia. Chagatai and Jochi were Genghis’s other famous sons, but neither served as regent after his death.