Uncas became the founder of the Mohegan branch of the Pequot in 1635 when he parted ways from his father-in-law, Sassacus. Uncas was renowned as a warrior, allying his forces with the English colonists in the Pequot War (1637) and defeating the rival Narragansett in 1643. Relations with the colonists were strained in 1661 when Uncas fought against Massasoit and the Wampanoag, who were also English allies. The name of Uncas was used as a fictionalized character in James Fenimore Cooper's The Last of the Mohicans (1826).