Just an interesting side note:
During Ghengis' rise to power, he viewed the Tartars (a great alliance of northern tribes) as a blood enemy, as his father Yesughei, who was the Khan of a relatively small tribe, (around 400-500 people, and only 200 warriors, the name of the tribe is widely known as "The Blue Wolves", although this is an anglicanisation) was killed by Tartars when Ghengis was in his teens. This in turn lead to him and his family being expelled from their tribe and left for dead in a desolate area, with absolutely nothing, no bows, no blades, and not even a single ger to shelter the eight of them.
Amazingly he forged together small groups of exiles (some of whom had never lived in a tribe) into his own, tiny tribe. They ventured north to "bleed the blood from the northern devils" (the Tartars). Through this action he became well known to Togral, the Khan of the Kerait tribe, and a former ally of his father. Togral was no warrior, but he applauded Temujin's effort and was persuaded to place men under Temujin's (Ghengis' birth name, he was still known by it at this time) command, in order to help him bleed the Tartars, who were an enemy of the Kerait.
Temujin's party of around 100-150 men managed to antagonize the Tartars into such a state that they marshaled a huge army, from all of their tribes, this army was around 1000-1200 strong, and even with the command of all of the Kerait's warriors Temujin still only had around 500-600 men (these odds may seem laughably easy compared to the battle of Badger's Mouth, but these were still the early days for Temujin, and he was fighting horse archers whose individual skills rivaled that of the men Temujin commanded.
In the weeks before the inevitable battle between the Tartars and the Kerait, as well as Temujin's young tribe, there was an unsuspected arrival.
The Blue Wolves, still lead by the same man who had left Temujin's family for dead (who Temujin and his family hated with a passion, funnily enough), arrived promising to aid Temujin and the Kerait for 1/3 of the loot, a proposed split between the three tribes, although the Wolves' 200 men only made up around 1/4 of the total Mongol force.
The battle plans were drawn up, they would rely upon the horns formation (which was the primary formation the Wolves and Temujin's raiding party used), where the two flanks would advance ahead of the body of the Mongol force and surround the Tartars. Temujin's tribe and the Kerait he had commanded in his northern raids took the left flank, and the Wolves took the right, with the majority of the Kerait making up the body of the Mongol army.
In the coming weeks Temujin fiercely drilled every Wolf and Kerait warrior in discipline and the tactics that would be used in the coming battle, this, combined with the fact that Temujin had commanded many Kerait warriors (who then viewed him as much more of a leader than the slothful Togral) and Temujin's birth right to lead the Wolves, instilled a deep sense of loyalty into the majority of the Mongols present.
The battle was a complete success, with the Mongols reportedly taking only a hundred or so casualties, but the real drama had yet to play out.
It is said that as the celebration of their victory rang on Temujin, although injured, challenged the leader of the Wolves to a duel to the death. If Temujin won, he would have command and complete loyalty of the Wolves, and if his father's usurper won, he would be rid of a troublesome loose end, and he would have Temujin's tribe's share of the loot.
Temujin won the duel, killing the usurper and taking command of the Wolves. It is around this time that Temujin found out that the Tartars were not entirely to blame for his father's death. He discovered that the leader of the Olkhunut, who was Yesukhei's brother by marriage and Temujin's uncle; and a supposed ally of the Wolves, had betrayed his father, telling the Tartars of his whereabouts when he was travelling alone. The Tartars had a grudge against Yesughei, for he had killed the leader of a Tartar raiding party. As it happens the leader of the raiding party was the son of a great Tartar Khan, and the son was named Temujin, and it was after him that Yesughei named his own son.
Temujin travelled to the Olkhunut with a small party of companions, his brothers and two of his most trusted men, Arslan and his son Jelme, who had freed Temujin when he had once been captured by the Wolves.
Upon arriving he was granted a meeting with his uncle (the khan of the Olkhunut), although he and his companions were stripped of their weapons. Records show that Temujin killed his Uncle in vengeance within his own ger, in the heart of his Uncle's tribe, with hundreds of Olkhunut warriors outside, with a loose piece of his own scale armor (which he had adapted from Jin designs).
It's remarkable that Temujin survived this encounter, and it's unbelievable that he managed to claim the Olkhunut as his own (he was after all the nephew of their, now deceased, Khan). In the space of months Temujin had gone from the leader of a small raiding party, of no more than 30 men, to the leader of two tribes (which he amalgamated into one) and over 800 warriors.
When returned north to the Kerait tribes, Togral feared he had come to usurp him from command of the Kerait, and ordered three of his best men to kill Temujin in his sleep. Foolishly the man Togral selected to lead these would-be assassins had served directly under Temujin in their early raids. The man's loyalties laid with Temujin, and when he entered Temujin's ger that night he warned Temujin, and killed the other two men who had come to assassinate Temujin. Togral had fled by the next morning, and left the Kerait behind.
Naturally Temujin joined the Kerait with his own tribe, and this was the birth of the Mongol nation, and the birth of his title, Ghengis Khan.