The French and Indian War (1754–63) comprised the North American theater of the worldwide Seven Years' War of 1756–63. It pitted the colonies of British America against those of New France. Both sides were supported by military units from their parent countries, as well as by American Indian allies. At the start of the war, the French North American colonies had a population of roughly 60,000 settlers, compared with 2 million in the British North American colonies. The outnumbered French particularly depended on the Indians. The European nations declared war on one another in 1756 following months of localized conflict, escalating the war from a regional affair into an intercontinental conflict.