During the Peninsular War, to prepare for the invasion of France, General Arthur Wellesley, the future Duke of Wellington, had to clear the potential menace posed by General Louis Rey and his garrison of 3000 men in San Sebastián: the port and fortress was a French strongpoint and a threat to the supply lines of any army moving into France. Positioned on the northern coast of Spain, overlooked to the north by Monte Urgull and the Castle of La Mota, the town stood across a narrow isthmus with its approach from the south protected by a formidably strong fortification known as the Hornwork. The siege of San Sebastián lasted from 7 July until 8 September and the attack resulted in the ransacking and devastation of the town by fire, and General Louis Rey finally surrendered on 8th September 1813.