The Iroquoian confederacy was organized sometime between 1400 and 1600 for the purpose of maintaining peaceful relations between the five constituent tribes. Subsequent to European contact relations within the confederacy were sometimes strained as each of the five tribes sought to expand and maintain its own interests in the developing fur trade. For the most part, however, the fur trade served to strengthen the confederacy because tribal interests often complemented one another and all gained from acting in concert. The League was skillful at playing French and English interests off against one another to its advantage and thereby was able to play a major role in the economic and political events of northEastern North America during the seventeenth and eighteenth centuries. The Iroquois aggressively maintained and expanded their role in the fur trade and as a result periodically found themselves at war with their neighbors, such as the Huron, Petun, and the Neutral to the west and the Susquehannock to the south. Much of the fighting was done by the Seneca, the most powerful of the Iroquoian tribes.
From 1667 to the 1680s the Iroquois maintained friendly relations with the French, and during this time Jesuit missions were established among each of the five tribes. Iroquois aggression and expansion, however, eventually brought them into conflict with the French and, at the same time, into closer alliance with the English. In 1687, 1693, and 1696 French military expeditions raided and burned Iroquois Villages and fields. During Queen Anne's War (1702-1713) the Iroquois allied with the English and at the war's end were acknowledged to be British subjects, though they continued to aggressively maintain and extend their middleman role Between English traders at Fort Orange (Albany) and native groups farther west. The victory of the English over the French in North America in 1763 weakened the power of the Confederacy by undermining the strategic economic and Political position of the tribes and by promoting the rapid Expansion of White settlement.
When the American Revolution broke out in 1775 neither the League as a whole nor even the tribes individually were able to agree on a common course of action. Most of the Iroquois allied with the British and as a result during and after the Revolution were forced from their homelands. In the period following the American Revolution the members of the Iroquois tribes settled on reservations in western New York state, southern Quebec, and southern Ontario, where many of their descendants remain today.