Uncas, c.1588-c.1683, chief of the Mohegan. Uncas was a subchief of the Pequot, but because of trouble with the chief, Sassacus, he withdrew with his followers and formed a separate tribe, the Mohegan. These people flourished under Uncas's leadership. Uncas was ambitious and sought British support. He was constantly at war with Miantonomo, the Narragansett chief. Both sided with the British in the Pequot War, but despite a treaty of peace (1638) signed between them through the instrumentality of the British, trouble continued. Uncas finally captured Miantonomo in 1643 and killed him, with British acquiescence. For the remainder of his life Uncas was involved in various troubles with the British and other Native Americans.