By May, 1637, when the first general court of Connecticut convened at Hartford, upward of thirty persons had fallen beneath the tomahawk.  The promptest measures were necessary; and without waiting for the assistance of Massachusetts, whose indiscretion had brought on the war, ninety men (nearly half the effective force of the colony) were raised,[8] and placed under the command of Captain John Mason, an officer who had served in the Netherlands under Sir Thomas Fairfax.  The force sailed down the river in three small vessels, and were welcomed at Fort Saybrook by Lieutenant Gardiner.

The Indian fort was situated in a swamp to the east of the Connecticut on the Mystic River; but instead of landing at the Pequot River, as he had been ordered, Mason completely deceived the Indian spies by sailing past it away from the intended prey.  Near Point Judith, however, in the Narragansett country, Mason disembarked his men; and, accompanied by eighty Mohegans and two hundred Narragansetts, turned on his path and marched by land westward towards the Pequot country.  So secretly and swiftly was this movement executed that the Indian fort was surrounded and approached within a few feet before the Indians took alarm.[9]

The victory of Mason was a massacre, the most complete in the annals of colonial history.  The English threw firebrands among the wigwams, and in the flames men, women, and children were roasted to death.  Captain Underhill, who was present, wrote that “there were about four hundred souls in this fort, and not above five of them escaped out of our hands.”  Only two white men were killed, though a number received arrow wounds.[10]

Mason, as he went to the Pequot harbor to meet his vessels, met a party of three hundred Indians half frantic with grief over the destruction of their countrymen, but contented himself with repelling their attack.  Finally, he reached the ships, where he found Captain Patrick and forty men come from Massachusetts to reinforce him.  Placing his sick men on board to be taken back by water, Mason crossed the Pequot River and marched by land to Fort Saybrook, where they were “nobly entertained by Lieutenant Gardiner with many great guns,” and there they rested the Sabbath.  The next week they returned home.[11]

The remnant of the Pequots collected in another fort to the west of that destroyed by Mason.  Attacked by red men and white men alike, most of them formed the desperate resolve of taking refuge with the Mohawks across the Hudson.  They were pursued by Mason with forty soldiers, joined by one hundred and twenty from Massachusetts under Captain Israel Stoughton.  A party of three hundred Indians were overtaken and attacked in a swamp near New Haven, and many were captured or put to death.  Sassacus, the Pequot chief, of whom the Narragansetts had such a dread as to say of him, “Sassacus is all one God; no man can kill him,” contrived to reach the Mohawks, but they cut off his head and sent it as a present to the English.[12]