Sassacus (Massachusett: Sassakusu (fierce)) (c. 1560 – June 1637) was born near present-day Groton, Connecticut. He was a Pequot sachem, and he became grand sachem after sachem Tatobem was killed in 1632. The Mohegans led by sachem Uncas rebelled against domination by the Pequots. Sassacus and the Pequots were defeated by the English along with their Narragansett and Mohegan allies in the Pequot War.
Sassacus fled to what he thought was safety among the Iroquois Mohawks in present-day New York, but they murdered him. They sent his head and hands to the English as a symbolic offering of friendship with the Connecticut Colony.
- Oberg, Michael Leroy, Uncas, First of the Mohegans, 2003, ISBN 0-8014-3877-2
- Vaughan, Alden T. (1995). New England Frontier: Puritans and Indians, 1620-1675, p. 150. University of Oklahoma Press. ISBN 0-8061-2718-X, ISBN 978-0-8061-2718-7