The Pequot War in 1637 saw the virtual elimination of the Pequot Indians as a tribe. The Massachusetts and Connecticut settlers from England and their allies captured or killed most of the Pequots.

Background
In the 1630s, the Connecticut River Valley was in turmoil. The Dutch traders and English settlers were each striving to include the area in within the sphere of influence of their colonies in New Amsterdam and Massachusetts respectively. The Indian tribes were contending with each other for dominance and control of the European trade. The Indian population was severely reduced in 1634 by the latest in a series of smallpox epidemics.

By 1636, the Dutch had fortified their trading post, and the English had built a trading fort at Saybrook. Farmers and crafters from Massachusetts had settled at the new river towns of Windsor, Hartford and Wethersfield.

The very word Pequot is derived from an Algonquian language phrase meaning "the destroyers". They had moved into southeastern Connecticut in the area around the Pequot River and the Mystic River some time before European contact and dominated or eliminated the tribes there. They were aggressively working to extend their area of control in all directions, at the expense of the Wampanoag to the north, the Narragansett to the east, the Connecticut Valley tribes to the west, and the Long Island tribes to the south.

Participants
Any single narrative description of the War tends to be confusing because of the number of parties involved. From a distance of several hundred years, many of these are unrecognized, since they have been consolidated into larger states. There were several independent colonies involved, each of which had its own leadership. There were also several tribes of native Americans, sometimes dealt with in summary based on their alliances or tributary status at the time. Participants included:

Massachusetts Bay Colony, Governors Henry Vane and John Winthrop, Captains John Underhill and John Endicott;
Plymouth Colony, Governor Edward Winslow and William Bradford;
Connecticut, Leader Thomas Hooker, Captain John Mason;
Pequot tribe, Sachem Sassacus;
Niantic tribe, Sachem Sassious;
Mohican tribe (sometimes written Mohegan), Sachem Uncas;
Narragansett tribe, Sachem Miantonomoh;
Metoac tribe (sometimes referred to as Montauk).

Causes for war
Before the war formally began, efforts to control fur trade access resulted in a series of escalating incidents and attacks and increased tensions on both sides. The split between the Pequot and Mohican widened as they aligned with different trade sources, the Mohican with the English and the Pequot with the Dutch. The Pequots attacked a group of Mattabesic Indians who attempted to trade at Hartford. Tension also increased as Massachusetts began to manufacture wampum, the supply of which the Pequots had formerly controlled.

In 1634 a trader, John Stone, and his crew were killed by a tribe that was a client of the Pequots. Stone had sailed from Boston and they protested his killing but the Pequot sachem, Sassacus, refused any demands. While this increased tensions, there was no other action. Stone was actually from the West Indies and had been banished from Boston for his behavior.

Then on July 20, 1636 a respected trader named John Oldham was attacked on a trading voyage to Block Island. He and several of his crew were killed and his ship looted. The Massachusetts Bay colony's retaliation is viewed as the start of actual war.

Battles
News of Oldham's death became the subject of sermons in the Massachusetts Bay Colony. In August, Governor Vane sent Captain John Endicott to exact punishment on the Indians of Block Island. Endicott's party of about 90 men sailed to Block Island and attacked the Niantic village. Most of the natives escaped, but 14 were killed, while two of Endicott's men were injured. Seeing this as unsuccessful, the English burned the village and what crops they couldn't carry away. He then went on to Fort Saybrook.

The men at Saybrook were not happy about the raid, but agreed that some of them would accompany Endicott as guides. He sailed back up the coast to a Pequot village, where he repeated last year's demand of payment for the death of Stone and more for Oldham. After some discussion he concluded that they were stalling and attacked. But the stall had worked, and all the residents escaped into the woods. He had to content himself with again burning the village and crops before sailing for home.

Pequot raiders
The Massachusetts' force had gone home, but the Connecticut settlers were left to deal with the Pequot anger. The Pequots sent war messages to their allies, but even though they claimed thirty-six tributary villages, this was only partly effective. The Western Niantic joined them, but the Eastern Niantic remained neutral. The Mohican and Narragansett openly sided with the English. The Narragansett had warred with and lost territory to the Pequots in 1622. Now their friend Roger Sherman urged them to take the English side.

Through the fall and winter, Fort Saybrook was effectively besieged. Any who ventured outside were killed. As spring arrived in 1637 the Pequot stepped up their raids on the Connecticut towns. On April 12 a raid at Weathersfield killed nine men and women, a number of cattle and horses, and took two girls as hostages. In all, the towns lost about thirty settlers in these raids.

In May, the river towns met in Hartford. (see: History of Connecticut). They raised the militia and put Captain John Mason in command. He set out with 90 militia and 70 Mohican warriors under Uncas to repay the Pequots. At Fort Saybrook, he was joined by Captain Underhilll and another twenty men. They proceeded to the principle Pequot village, near modern Groton, but the Pequot chose to simply defend their fortified village and Capt. Mason did not have the forces to take it, so he sailed east. He stopped at the village of Misistuck (Mystic), but the scene was repeated.

The Mystic Massacre
Believing that the English had returned to Boston, the Pequot sachem Sassacus took several hundred of his warriors to make another raid on Hartford. But, Mason had only gone to visit the Narragansett, who joined him with several hundred warriors. He also picked up some Niantic braves. With his force up to about 400, on May 26, 1637 they attacked the Pequot palisade at Mystic by surprise, having come overland. A part of Mystic's warriors had accompanied Sassacus, but the fort contained over 500 Pequots, including women and children. Surrounding it they set it afire, and Mason ordered any who escaped the flames killed. Only a handful made it to the woods, and in an hour all the rest were dead.

Believing the mission accomplished, they all set out for home. The militia became temporarily lost, but in doing so they narrowly missed the returning war party. They suffered only two dead and about twenty wounded in the battle. Their allies were not so lucky, and half of them never made it home.

The Pequots hunted down
The slaughter at Mystic broke the Pequots, and deprived them of their allies. They abandoned their villages and fled mostly in small bands to seek refuge with other tribes. Many were hunted down by the Mohican and Narragansett warriors. The largest group, led by Sassacus, was denied aide by the Metoac on Long Island. So, he led about 400 west along the coast towards the Dutch at New Amsterdam and their Indian allies. But when they crossed the Connecticut River, they killed three men they encountered near Fort Saybrook.

In mid-June, John Mason set out from Saybrook with 160 men and 40 Mohican scouts under Uncas. They caught up with the refugees at Sasqua, a Mattabesic village near modern Fairfield. Surrounded in a nearby swamp, they refused to surrender. Several hundred, mostly women and children were allowed to leave with the Mattabesic. In the ensuing battle, Sassacus was able to break free with perhaps 80 warriors, but 180 of the Pequot were killed or captured.

Sassacus and his followers had hoped to gain refuge among the Mohawk in modern day New York. However, the Mohawk had seen the display of English power and chose instead to slaughter Sassacus and his warriors, sending Sassacus' scalp to Hartford as a symbolic offering of Mohawk friendship with the young Connecticut Colony. Remaining bands were hunted down, and the War was over.

Aftermath
In September the victorious tribes met with the General Court of Connecticut and agreed on the disposition of the Pequots and their lands. The agreement was known as the first Treaty of Hartford, and was signed on September 21, 1638. Prisoners were distributed as slaves to the Mohican, Narragansett, and Metoac tribes. Some of the elderly not wanted by the tribes became household servants in Connecticut and Massachusetts. The colonists gained the Pequot lands, and the Pequot were officially declared not to exist. However, a remnant was later recovered from captivity and assigned to reservations in Connecticut.

This was the first time the New England Indians had encountered the European version of warfare. The idea of a total war was essentially new to them. After the war, the colonists represented such a power that no tribe or group of tribes would stand against them for a generation. There was a fairly long period of peace until continued population pressure resulted in the general uprising known as King Philip's War in 1675.