Chagatai Khan

Chagatai Khan (Mongolian: ᠴᠠᠭᠠᠲᠠᠶ; c. 1184 – 1242) was a son of Genghis Khan, a prominent figure in the early Mongol Empire, and the first khan of the Chagatai Khanate. The second son of Genghis's wife Börte, Chagatai was renowned for his masterful knowledge of Mongol custom and law, which he scrupulously obeyed, as well as his harsh temperament. Because Genghis felt that he was too inflexible in character, most notably never accepting the legitimacy of his elder brother Jochi, he excluded Chagatai from succession to the Mongol throne. He was nevertheless a key figure in ensuring the stability of the empire after Genghis's death and during the reign of his younger brother Ögedei Khan.

Chagatai held military commands alongside his brothers during the Mongol conquest of the Jin dynasty in 1211 and the invasion of the Khwarazmian Empire in 1219. During the latter, he was appointed to a key role in organising logistics in addition to battlefield responsibilities, but was censured after feuding with Jochi during the Siege of Gurganj. After the campaign, Chagatai was granted large tracts of conquered land in Central Asia, which he ruled until his death. He quarrelled with civil officials such as Mahmud Yalavach over matters of jurisdiction and advised Ögedei on questions of rulership. Chagatai died shortly after Ögedei in 1242; his descendants ruled his territories as the eponymous Chagatai Khanate.