Dummer's War (1722–1725) is also known as Father Rale's War, Lovewell's War, Greylock's War, the Three Years War, the Wabanaki-New England War, or the 4th Anglo-Abenaki War. It was a series of battles between the New England Colonies and the Wabanaki Confederacy (specifically the Miꞌkmaq, Maliseet, and Abenaki), who were allied with New France. The eastern theater of the war was located primarily along the border between New England and Acadia in Maine, as well as in Nova Scotia; the western theater was located in northern Massachusetts and Vermont at the border between Canada (New France) and New England. During this time, Maine and Vermont were part of Massachusetts.The root cause of the conflict on the Maine frontier concerned the border between Acadia and New England, which New France defined as the Kennebec River in southern Maine.: 27, 266  Mainland Nova Scotia came under British control after the Siege of Port Royal in 1710 and the Treaty of Utrecht in 1713 (not including Cape Breton Island), but present-day New Brunswick and Maine remained contested between New England and New France. New France established Catholic missions among the four largest Indian villages in the region: one on the Kennebec River (Norridgewock), one farther north on the Penobscot River (Penobscot Indian Island Reservation), one on the Saint John River (Meductic Indian Village / Fort Meductic),: 51, 54  and one at Shubenacadie, Nova Scotia (Saint Anne's Mission). Similarly, New France established three forts along the border of New Brunswick during Father Le Loutre's War to protect it from a British attack from Nova Scotia.

The Treaty of Utrecht ended Queen Anne's War, but it had been signed in Europe and had not involved any member of the Wabanaki Confederacy. The Abenaki signed the 1713 Treaty of Portsmouth, but none had been consulted about British ownership of Nova Scotia, and the Miꞌkmaq began to make raids against New England fishermen and settlements. The war began on two fronts as a result of the expansion of New England settlements along the coast of Maine and at Canso, Nova Scotia. The New Englanders were led primarily by Massachusetts Lieutenant Governor William Dummer, Nova Scotia Lieutenant Governor John Doucett, and Captain John Lovewell. The Wabanaki Confederacy and other Indian tribes were led primarily by Father Sébastien Rale, Chief Gray Lock, and Chief Paugus.

During the war, Father Rale was killed by the British at Norridgewock. The Indian population retreated from the Kennebec and Penobscot rivers to St. Francis and Becancour, Quebec, and New England took over much of the Maine territory.