The Spanish invasion of Portugal between 5 May and 24 November 1762 was a main military episode of the wider Seven Years' War, where Spain and France were heavily defeated by the Anglo-Portuguese Alliance (including broad popular resistance). It initially involved the forces of Spain and Portugal, before the French and British intervened in the conflict on the side of their respective allies. The war was also strongly marked by a national guerilla warfare in the mountainous country, cutting off supplies from Spain and a hostile peasantry that enforced a scorched earth policy as the invading armies approached, leaving the invaders starving and short of military supplies.