After the French surrender to Germany, Britain needed to maintain naval supremacy in the Mediterranean, secure key naval ports in French North Africa and prevent the French fleet falling into German hands. Churchill assembled Force H and launched Operation Catapault to secure the French vessels at Mers el Kébir, a powerful fleet which was under the command of a Vichy loyalist commander. On arrival at Mers el Kébir, the French refused to cooperate. The British issued an ultimatum that the ships must be transferred, surrendered or destroyed. The order was refused, and prompted the French to request naval back up. When the British were warned of a possible offensive, they reluctantly opened heavy fire on the French fleet; ships were hit and over 1,000 French lives were lost. Practically, a powerful fleet of ships never fell into German hands. Politically, Anglo-French relations were damaged. Nevertheless the rest of the world received a clear message about the strength of Britain’s will to win the war.