King William's War was the North American theater of the Nine Years' War (1688–1697). It was the first of six colonial wars (see the four French and Indian Wars, Father Rale's War and Father Le Loutre's War) fought between New France and New England along with their respective Native allies before France ceded its remaining mainland territories in North America east of the Mississippi River in 1763.

For King William's War, neither England nor France thought of weakening their position in Europe to support the war effort in North America. New France and the Wabanaki Confederacy were able to thwart New England expansion into Acadia, whose border New France defined as the Kennebec River in southern Maine.: 27  According to the terms of the 1697 Peace of Ryswick that ended the Nine Years' War, the boundaries and outposts of New France, New England, and New York remained substantially unchanged.

The war was largely caused by the fact that the treaties and agreements that were reached at the end of King Philip's War (1675–1678) were not adhered to. In addition, the English were alarmed that the Indians were receiving French or maybe Dutch aid. The Indians preyed on the English and their fears, by making it look as though they were with the French. The French were fooled as well, as they thought the Indians were working with the English. These occurrences, in addition to the fact that the English perceived the Indians as their subjects, despite the Indians' unwillingness to submit, eventually led to two conflicts, one of which was King William's War.