Invasion of Isle de France

The Invasion of Isle de France was a complicated but successful British amphibious operation in the Indian Ocean, launched in November 1810 during the Napoleonic Wars. During the operation, a substantial military force was landed by the Royal Navy at Grand Baie, on the French colony of Isle de France (now Mauritius). Marching inland against weak French opposition, the British force was able to overwhelm the defenders in a series of minor engagements, culminating in the capture of the island's capital Port Napoleon and the surrender of Charles Decaen, the French governor. The surrender eliminated the last French territory in the Indian Ocean and among the military equipment captured were five French Navy frigates and 209 heavy cannon. Isle de France was retained by Britain at the end of the war under the name of Mauritius and remained part of the British Empire until 1968.

Background

The operation was the culmination of two years of conflict over the island and the neighbouring Île Bourbon between frigate squadrons commanded by Josias Rowley and Jacques Hamelin. Hamelin repeatedly raided British trade convoys and Rowley responded with amphibious assaults on French harbours, but neither had gained ascendancy by the time Rowley sent most of his force to attack the port of Grand Port on Isle de France in August 1810. At the ensuing battle at Grand Port the British squadron was destroyed and Hamelin began to blockade Rowley on Île Bourbon. As British reinforcements were urgently dispatched, several actions were fought between recently arrived British ships and the more numerous French forces. At the last of these on 18 September 1810, Hamelin was defeated and captured by Rowley. This allowed Rowley to build his forces over the next two months until they were sufficient for a successful invasion, which was led by the recently arrived Admiral Albemarle Bertie.

The Indian Ocean had been an important strategic region for British trade since the first British trading posts were developed in India. By the Napoleonic Wars, millions of pounds worth of goods crossed the ocean's trade routes every year, mostly in the heavily guarded convoys of East Indiamen.Gardiner, p. 92 The French recognised the economic importance of these convoys but until 1808 failed to provide sufficient forces to disrupt the Indian trade. Late in 1808, it was decided to send a strong frigate squadron to the Ocean under the command of Jacques Hamelin to augment the forces available on the island bases of Île Bonaparte and Isle de France and raid British shipping in the region. Hamelin was an able commander and between May 1809 and July 1810 his ships captured seven East Indiamen and a large number of small merchant ships and warships.Gardiner, p. 93

The British response to Hamelin's deployment was provided by Admiral Albemarle Bertie, who collected a squadron of ships from those available at the Cape of Good Hope and placed them under the command of Commodore Josias Rowley.James, Vol. 5, p. 192–195 Bertie gave Rowley instructions to blockade the islands and prepare for invasion attempts once the required forces could be spared. During 1809 and the spring of 1810, Rowley maintained the blockade and launched a series of small raids, the largest being at Saint Paul on Île Bonaparte in September 1809. By July 1810, Rowley had developed sufficient forces at his island base on Rodriguez to successfully invade and capture Île Bonaparte, which he restored to its former name of Île Bourbon.James, Vol. 5, p. 272 In August, Rowley attempted to extend his blockade of Isle de France by seizing small islands off the main ports that could control the passage of shipping through the coral reefs that surround the island. The first operation was to capture Île de la Passe off Grand Port, which was successfully secured on 13 August. Shortly afterwards a French squadron forced passage into the harbour and Captain Samuel Pym ordered the four frigates of the blockade squadron to attack the ships anchored in the bay. The ensuing Battle of Grand Port was a disaster for the British, as two frigates were wrecked on the reefs and two others captured with their entire crews: only the very seriously wounded, including Captain Nesbit Willoughby, were repatriated to Île Bourbon.James, Vol. 5, p. 295

With his squadron reduced to a single frigate, Rowley sent urgent messages to the British bases at Madras and Cape Town requesting reinforcements. The naval authorities responded by sending the forces they had available to join Rowley at Rodriguez. The first two frigates to arrive, HMS ''Africaine'' and HMS ''Ceylon'' were both attacked while sailing alone and captured by Hamelin's squadron, which was now blockading Île Bourbon. Rowley was able to recapture both ships within hours of their loss, and was also able to seize Hamelin and his flagship '' Vénus'' at the action of 18 September 1810.Woodman, p. 293 The loss of the French naval commander was a serious blow to the squadron on Isle de France, which was also beset by supply problems resulting from a lack of naval stores and food supplies. Unable to make the lengthy cruises needed to disrupt the Indian Ocean trade routes, they were forced to remain in harbour as Rowley was heavily reinforced during September and October 1810,James, Vol. 5, p. 324 and eventually the senior naval officer, Captain Jean Dornal de Guy, had his four frigates, ''Manche