St Clair's force was made up of the 1st Battalion of the Royal Regiment, the 5th Battalion of the Highlanders Regiment, the 3rd Battalion of Bragg's Regiment, the 2nd Battalion of Harrisson's Regiment, the 4th Battalion of Richbell's Regiment, part of some battalions from Frampton's Regiment and some companies of marines, numbering a total of 4,500 men. The commanders were doubtful as to whether Brittany was the best target for the raid, preferring Normandy. Brittany was not well-known to the British - St Clair could not acquire a map of the region and had to use a small-scale map of France instead, whilst Lestock knew nothing about the town's defences. The landing force was also unable to acquire horses. The fleet left Plymouth on 26 September and passed Ushant without being intercepted by the French. The French staff had been informed of the importance of the troops stationed at Plymouth by their intelligence services through interrogating British prisoners, but this had not revealed the force's intended target. An agent on the ground sent a message that the force had little food and few horses, suggesting a small-scale raid on the French coast. The commanders of French ports on the English Channel and Atlantic coasts were notified, notably Port-Louis on 24 September. Coastguard militias were sent to the coast, though British reconnaissance along the coast went unreported. At the same time ships under Mac Nemara were ordered to head for Lorient and wait. At the end of the 17th century, the coast of Brittany was gradually covered in new fortifications, but the area around Lorient itself was still poorly defended. The citadelle de Port-Louis which closed off the Lorient roads had not been modernised and only low ramparts protected the city's rear, whilst its coast had no other defences. The place had become a trading port and a strategic point. Arsenals were built to construct ships for the French navy and the East India Company - the latter had chosen to move its base from Nantes to Lorient in 1732. It was also a centre for cabotage between Brest, Nantes and Bordeaux. To the town's south-east, Belle-Île gave shelter to ships returning from the East Indies and heading for Lorient. The nearby islands of Houat and Hoëdic were fortified at the end of the 17th century to defend the approaches to the main island. A cult of the Virgin Mary developed in the area from the 1620s onwards.