Which son of Genghis Khan gave his name to the Chagatai Khanate?

Chagatai Khan gave his name to the Chagatai Khanate.

Chagatai Khan was the second son of Genghis Khan and Börte, and the territories assigned to him and his descendants became known as the Chagatai Khanate, or Chagatai Ulus. He was therefore the dynasty’s eponym—the person whose name identifies the political realm.

Chagatai was famous for his strict knowledge of Mongol custom and law. Genghis Khan considered him unsuitable to inherit the empire’s central throne partly because of his severe temperament and hostility toward his elder brother Jochi. Instead, Ögedei was chosen as successor, while Chagatai received lands in Central Asia, including areas around the former Qara Khitai realm and Transoxiana.

The khanate was not fully independent at first and remained subject to the Great Khan. After the Mongol Empire fractured politically in the later thirteenth century, it functioned as a separate Central Asian state. Its ruling house survived for centuries, and “Chagatai” also became associated with a major literary Turkic language. Ögedei, Tolui, and Jochi were brothers of Chagatai, but none gave his name to this khanate.