From Assassin's Creed III - The son of British Templar Haytham Kenway and Kaniehtí:io, a Kanien'kehá:ka woman from the village of Kanatahséton, grew up in Kanatahséton. In 1760, when he was still a young child, he was assaulted by Charles Lee and other Colonial Templars seeking the Isu temple, which the Kanien'kehá:ka were protecting, and lost his mother shortly thereafter, when their village was burned down by colonial forces.

Concerned by the outside world's impact on his people, Ratonhnhaké:ton eventually joined the Assassin Brotherhood on the advice of Oiá:ner and the Isu Juno, in order to protect his village and prevent the Templars from returning. Finding the Templars had wiped out the Colonial Assassins years prior, Ratonhnhaké:ton convinced the retired Assassin Mentor Achilles Davenport to train him and adopted the more Western-sounding pseudonym of 'Connor'.

During his hunt for the Templars, Ratonhnhaké:ton aided the Patriot movement and protected George Washington, unwittingly becoming an important figure of the American Revolution. However, he was conflicted between his desire to reconcile with his father, despite Achilles' warnings as to the futility of uniting the Assassin and Templar philosophies, and his dogged pursuit of Charles Lee, whom Haytham staunchly supported.

Upon learning that it was Washington, not Lee, who had burned his village, Ratonhnhaké:ton became disillusioned with the Revolutionaries but continued using them to aid in the eradication of the Templars. He reluctantly accepted Washington's request for help in investigating Benedict Arnold and then in disposing of an Apple of Eden he had recovered. The latter incident saw Ratonhnhaké:ton trapped in an alternate reality constructed by the Apple, one wherein Washington ruled as king through tyranny. Eventually, Ratonhnhaké:ton escaped this reality and disposed of the Apple.

Following Achilles' death, Ratonhnhaké:ton successfully eliminated the Colonial Templars, including his father, and went on to rebuild and lead the Colonial Assassins in the newly formed United States of America. In this capacity, he expanded the Assassin network in the New World and reconnected a number of previously detached Brotherhoods across the region.