OPERATION CATAPULT, JULY 3, 1940: The Royal Navy attacks the French fleet at Mers-el-Kebir.

In 1940, the French fleet was the fourth largest naval force in the world after Britain, the United States and Japan. Its strength included seven battleships, 19 cruisers, 71 destroyers and 76 submarines. Shortly after the Germans attacked France on May 10, 1940, most of the vessels in French ports sailed to other harbors. A powerful French naval force was anchored at Mers-el-Kebir, just to the west of the French Algerian port of Oran.

Churchill knew that the French warships could not be allowed to fall into the hands of the Axis. If Germany and Italy could add these units to their existing naval force, Britain would face an overwhelming threat that it could not adequately meet.