Börte occupied a senior place in the household and political network of Temüjin, later Genghis Khan. Her marriage brought an alliance with the Onggirat and resources including the sable coat used to renew Temüjin's connection with the Kerait ruler Toghrul. After her abduction by the Merkit, Temüjin and his allies recovered her. The episode is preserved in the Secret History of the Mongols and later accounts, whose details and chronology do not always agree.

As chief wife, Börte managed people, herds and the resources of her own camp. Her four sons—Jochi, Chagatai, Ögedei and Tolui—formed the principal line considered for the imperial succession. Her daughters' marriages also joined the ruling family to important allies. This combination of household authority and dynastic standing gave her a role in the formation of the empire that cannot be reduced to the military activities of her husband.

The Secret History portrays her intervening in major family and political questions. It credits her with urging separation from Jamukha and with warning Temüjin about the shaman Teb Tengri's treatment of his brother. These speeches are literary representations of counsel, rather than verbatim records. During the conquests she maintained her court in the Mongol homeland, associated with the Kherlen region, while other wives accompanied campaigns. Her authority rested on resources, kinship and seniority within the imperial household. The dates of her final years remain uncertain.