Uncas was bilingual, learning Mohegan and some English, and possibly some Dutch.

In 1626, Owaneco arranged for Uncas to marry the daughter of the principal Pequot sachem Tatobem to secure an alliance with them. Uncas had a total of seven wives, each of them high ranking in their own rights in the community. Owaneco died shortly after Uncas's first marriage, and Uncas had to submit to Tatobem's authority. Tatobem was captured and killed by the Dutch in 1633; Sassacus