linguistic:translation
Early campaigns

Temüjin returned to Dei Sechen to marry Börte when he reached the age of majority at fifteen. Delighted to see the son-in-law he feared had died, Dei Sechen consented to the marriage and accompanied the newlyweds back to Temüjin's camp; his wife Čotan presented Hö'elün with an expensive sable cloak. Seeking a patron, Temüjin chose to regift the cloak to Toghrul, khan (ruler) of the Kerait tribe, who had fought alongside Yesügei and sworn the anda pact with him. Toghrul ruled a vast territory in central Mongolia but distrusted many of his followers. In need of loyal replacements, he was delighted with the valuable gift and welcomed Temüjin into his protection. The two grew close, and Temüjin began to build a following, as nökod such as Jelme entered into his service. Temüjin and Börte had their first child, a daughter named Qojin, around this time.

Soon afterwards, seeking revenge for Yesügei's abduction of Hö'elün, around 300 Merkits raided Temüjin's camp. While Temüjin and his brothers were able to hide on Burkhan Khaldun mountain, Börte and Sochigel were abducted. In accordance with levirate law, Börte was given in marriage to the younger brother of the now-deceased Chiledu. Temüjin appealed for aid from Toghrul and his childhood anda Jamukha, who had risen to become chief of the Jadaran tribe. Both chiefs were willing to field armies of 20,000 warriors, and with Jamukha in command, the campaign was soon won. A now-pregnant Börte was recovered successfully and soon gave birth to a son, Jochi; although Temüjin raised him as his own, questions over his true paternity followed Jochi throughout his life. This is narrated in the Secret History and contrasts with Rashid al-Din's account, which protects the family's reputation by removing any hint of illegitimacy. Over the next decade and a half, Temüjin and Börte had three more sons (Chagatai, Ögedei, and Tolui) and four more daughters (Checheyigen, Alaqa, Tümelün, and Al Altan).

The followers of Temüjin and Jamukha camped together for a year and a half, during which their leaders reforged their anda pact and slept together under one blanket, according to the Secret History. The source presents this period as close friends bonding, but Ratchnevsky questioned if Temüjin actually entered into Jamukha's service in return for the assistance with the Merkits. Tensions arose and the two leaders parted, ostensibly on account of a cryptic remark made by Jamukha on the subject of camping; in any case, Temüjin followed the advice of Hö'elün and Börte and began to build an independent following. The major tribal rulers remained with Jamukha, but forty-one leaders gave their support to Temüjin along with many commoners: these included Subutai and others of the Uriankhai, the Barulas, the Olkhonuds, and many more. Many were attracted by Temüjin's reputation as a fair and generous lord who could offer better lives, while his shamans prophesied that heaven had allocated him a great destiny.

Temüjin was soon acclaimed by his close followers as khan of the Mongols. Toghrul was pleased at his vassal's elevation but Jamukha was resentful. Tensions escalated into open hostility, and in around 1187 the two leaders clashed in battle at Dalan Baljut: the two forces were evenly matched but Temüjin suffered a clear defeat. Later chroniclers including Rashid al-Din instead state that he was victorious but their accounts contradict themselves and each other.

Modern historians such as Ratchnevsky and Timothy May consider it very likely that Temüjin spent a large portion of the decade following the clash at Dalan Baljut as a servant of the Jurchen Jin dynasty in North China. Zhao Hong recorded that the future Genghis Khan spent several years as a slave of the Jin. Formerly seen as an expression of nationalistic arrogance, the statement is now thought to be based in fact, especially as no other source convincingly explains Temüjin's activities between Dalan Baljut and c. 1195. Taking refuge across the border was a common practice both for disaffected steppe leaders and disgraced Chinese officials. Temüjin's reemergence having retained significant power indicates that he probably profited in the service of the Jin. As he later overthrew that state, such an episode, detrimental to Mongol prestige, was omitted from all their sources. Zhao Hong was bound by no such taboos.