Chagatai Khan was the second son of Genghis Khan and Börte and received a large ulus in Central Asia after the Mongol conquests. He was regarded as a strict defender of Mongol customary law and had a difficult relationship with his elder brother Jochi, whose legitimacy he challenged.
Chagatai supported Ögedei’s election as great khan, and his descendants ruled the Chagatai Khanate, although the state later divided and changed character. Chagatai Khan was born in Mongolia and died in Almaliq.
Conn Iggulden’s Bones of the Hills places Chagatai inside the succession problem created by Genghis Khan’s conquests. As the Mongol armies move west against Khwarazm, rivalry between Chagatai, Jochi and Ögedei makes the question of who will inherit authority almost as dangerous as the external war. Lords of the Bow shows the earlier formation of that problem, with Genghis’s sons growing up inside the campaigns that turn tribal leadership into imperial rule. Chagatai’s role across the two novels is therefore dynastic as well as military: he is one of the princes whose ability to command armies cannot be separated from the distrust and competition within the ruling family.