Pequot War: A combined English and Mohegan force under John Mason attacks a village in Connecticut, massacring approximately 500 Pequots.

The Mystic massacre also known as the Pequot massacre and the Battle of Mystic Fort took place on May 26, 1637 during the Pequot War, when Connecticut colonists under Captain John Mason and their Narragansett and Mohegan allies set fire to the Pequot Fort near the Mystic River. They shot anyone who tried to escape the wooden palisade fortress and killed most of the village in retaliation for previous Pequot attacks. There were between 400 and 700 Pequot civilians killed during the massacre, and the only Pequot survivors were warriors who were away in a raiding party with their sachem Sassacus.

The Pequot War was an armed conflict that took place between 1636 and 1638 in New England between the Pequot tribe and an alliance of the colonists from the Massachusetts Bay, Plymouth, and Saybrook colonies and their allies from the Narragansett and Mohegan tribes. The war concluded with the decisive defeat of the Pequot. At the end, about 700 Pequots had been killed or taken into captivity. Hundreds of prisoners were sold into slavery to colonists in Bermuda or the West Indies; other survivors were dispersed as captives to the victorious tribes.

The result was the elimination of the Pequot tribe as a viable polity in Southern New England, and the colonial authorities classified them as extinct. Survivors who remained in the area were absorbed into other local tribes.