In 1758 another British expedition under General Jeffrey Amherst besieged the fortress, beginning on June 8. The British had 39 ships with about 14 000 men, and a further landing force of 12 870 men. The fortress was defended by 10 French ships with 3870 men, and another 3920 French soldiers inside the fortress itself. The siege lasted until the British finally captured the fortress on July 26. The British suffered 200 deaths and 360 wounded, while the French had 410 deaths and about 400 wounded. The British also took 5640 French prisoners. By 1760 the British had destroyed the entire fortress.
Fortress Louisbourg has been designated a Canadian National Historic Site.
The placename is pronounced "Lewisberg" in spite of its French origins.