The Dutch, who had settled in the vicinity of New York, had been selling weapons to the Indian people known as the Five Nations (i.e. the Iroquois) and encouraging them to make war on other Indian tribes, including the Huron and Algonquin. The purpose was to divert the flourishing fur trade which the French had established with the Huron and Algonquin. The Iroquois' supply of pelts was quickly becoming depleted. Known variously as the Iroquois War and the Beaver War, the conflict that ensued was almost a war of survival for the Iroquois League, the confederation of the Five Nations.
On 03 August 1642, the Iroquois attacked the Huron along the Richelieu River. On 30 March 1644, they attacked the French settlement of Montreal.
The Iroquois honored a truce between 14 July 1645 and 18 October 1646. But they soon broke it by attacking and burning Fort Richelieu, which had been erected by the French at the mouth of the Richelieu River in 1642. The Iroquois carried out raids into the Huron country, launching a major offensive in 1649 and forcing the Huron to flee as far west as present-day Wisconsin.
By 1650, the Jesuit missionaries were also forced to leave the region by the Iroquois raids.
The Iroquois attacked and defeated the Tobaccos in 1650. Between 1650 and 1651 they vanquished the Neutrals.
The first Iroquois War officially came to a halt with the signing of a treaty of peace with the French on 05 November, 1653. But for all intents and purposes, the treaty was just a piece of paper. Between 1653 and 1656 the Iroquois made war upon the Erie.