In 1637 he helped the English under Colonel John Mason in a war against the Pequots and received part of their land as a reward.
Native tribes made war on Uncas several times, but with the help of the English he always defeated them. In 1643 he defeated and took prisoner Miantonomoh, the chief of the Narragansett, and later killed him.
Many complaints were made of his cruelty and injustice.