Fourth son of 成吉思汗 and a leading general in the wars against the Jin. He never became Great Khan, but his sons Möngke, 忽必烈 (Kublai) and Hulagu came to rule much of the Mongol empire.
His name means 'mirror' in Mongolian. When his brother 窝阔台 (Ögedei) fell gravely ill in 1232, the official history says Tolui offered his own life instead, drank a shaman's ritual water, and died.