In 1757 a British attempt to capture Louisbourg in North America had been frustrated by a build-up of French ships in the surrounding area. The French hoped to adopt a similar strategy for 1758, and decided to send the Brest fleet to boost their forces around Louisbourg. In November 1757 a French force of fifteen ships under Admiral La Clue sailed from Toulon, but following a storm on 30 November they were forced to take shelter in the port of Cartagena, in neutral Spain. They remained there as the British under Henry Osborn moved to bottle up the French in port. Osborn had orders to prevent the French from escaping from the Mediterranean. He received word that a French reinforcement of three ships-of-the-line had set sail from Toulon under Michel-Ange Duquesne de Menneville, intending to combine with La Clue. Two other ships, after failing to capture a British convoy, had also managed to slip into Cartagena to reinforce La Clue.