Khulan was the wife of Genghis Khan who was a daughter of the Merkit leader Dayir Usun. Her marriage followed Dayir Usun's submission to Temüjin during the campaigns against the Merkit confederation around 1203–1204.
Khulan was not simply an ordinary captive or political hostage. After meeting her, Temüjin accepted her as a wife, and she became one of the highest-ranking women in the imperial household. Her status was generally regarded as second only to that of Börte, Genghis Khan's principal wife.
Khulan maintained her own ordo, or large household and court, as Mongol royal wives did. She accompanied Genghis Khan during important campaigns, including the western war against the Khwarazmian Empire. She bore him a son, Kölgen, also called Gelejian in some sources.
The main confusion is with Alaltun, a daughter of Genghis Khan who was linked to the Uyghur ruling house, and with Yesugen, a Tatar woman who also became his wife. Börte was Genghis Khan's first and principal wife, not Dayir Usun's daughter.