During the French invasion of Portugal it was occupied in 1807 or 1808 by a detachment of 50 men, after its artillery pieces had been removed to the Citadel of Cascais to provide protection for Lisbon. The French were imprisoned by the local inhabitants after a group of students succeeded in persuading the invaders to surrender, convincing them that the Portuguese had received reinforcements. At the same time people from Nazaré travelled south by boat to Cascais in search of armaments, which enabled them to repel the French reinforcements that were heading from Peniche to the north, to aid the French garrison. The fort became a landmark of popular revolt but, later, the French invaders returned to the area, killing inhabitants and burning houses and boats in reprisal.