The Atlantic campaign of 1806 was a series of manoeuvres and counter-manoeuvres conducted by squadrons of the French Navy and the British Royal Navy across the Atlantic Ocean during the spring and summer of 1806, as part of the Napoleonic Wars. The campaign followed directly from the Trafalgar campaign of the year before, in which the French Mediterranean fleet had crossed the Atlantic, returned to Europe and joined with the Spanish fleet. On 21 October 1805, this combined force was destroyed by a British fleet under Lord Nelson at the Battle of Trafalgar, although the campaign did not end until the Battle of Cape Ortegal on 4 November 1805. Believing that the French Navy would not be capable of organised resistance at sea during the winter, the First Lord of the Admiralty Lord Barham withdrew the British blockade squadrons to harbour. Barham had miscalculated – the French Atlantic fleet, based at Brest, had not been involved in the Trafalgar campaign and was therefore at full strength. Taking advantage of the reduction in the British forces off the port, Napoleon ordered two heavy squadrons to sea, under instructions to raid British trade routes while avoiding contact with equivalent Royal Navy forces.
Departing from Brest on 13 December 1805, it was 12 days before the British Admiralty were aware of the French movements, by which time the French squadrons were deep in the Atlantic, one under Vice-admiral Corentin Urbain de Leissègues intending to cruise in the Caribbean and the other, under Counter-admiral Jean-Baptiste Philibert Willaumez, sailing for the South Atlantic. Two British squadrons were hastily mustered and dispatched in pursuit, one under the command of Rear-admiral Sir Richard Strachan and the other under Rear-admiral Sir John Borlase Warren. These squadrons were joined by a third under Rear-admiral Sir John Thomas Duckworth, who had deserted his station off Cádiz when he learned news of a French squadron to his south and subsequently crossed the Atlantic in pursuit of Willaumez. Although Willaumez managed to escape into the South Atlantic, Leissègues was less successful and was discovered and destroyed at the Battle of San Domingo in February 1806 by a combined force under Duckworth and Rear-admiral Alexander Cochrane. Other squadrons already at sea became embroiled in the campaign: a smaller squadron that had been raiding the African coast under Commodore Jean-Marthe-Adrien l'Hermite since August 1805 provided a diversion to the major campaign but failed to draw off significant British forces, while the remnants of a French squadron under Counter-admiral Charles-Alexandre Léon Durand Linois that had been operating in the Indian Ocean since 1803 was intercepted and defeated by Warren in March, after a chance encounter on its journey back to France.
Willaumez achieved minor success in his operations in the South Atlantic and Caribbean, but was caught in a summer hurricane on his return journey and his ships were scattered along the Eastern Seaboard of North America. One was intercepted and destroyed by British forces and others were so badly damaged in the storm that they were forced to shelter in American ports. The survivors gradually returned to Brest during the autumn, the last arriving in early 1807. The campaign was the last significant operation in the Atlantic for the remainder of the war, and no French squadron of any size left any of the Biscay ports until 1808. The losses suffered by the Brest fleet weakened it so severely that it would not participate in a major operation until 1809, when an attempt to break out of Brest ended in defeat at the Battle of Basque Roads.
Background
Trafalgar
On 30 March 1805, the French Mediterranean Fleet under Vice-admiral Pierre-Charles Villeneuve successfully broke out of Toulon harbour, avoiding the British blockade fleet under Vice-admiral Lord Nelson and sailing westwards out of the Mediterranean and into the Atlantic, Nelson following several days behind. Villeneuve, joined by a Spanish squadron, crossed the ocean to the Caribbean and anchored at Martinique, while Nelson arrived at Barbados on 11 June. Panicked by the British arrival, Villeneuve immediately returned to Europe, with Nelson again close behind. Villeneuve's orders had specified that he sail to Brest, the French naval port on the Bay of Biscay, and join there with the fleet under Vice-admiral Honoré Ganteaume. Together this force would drive the Royal Navy out of the English Channel in preparation for an invasion of Britain. However, as he passed the Spanish port of Ferrol on 22 July 1805, Villeneuve was intercepted by a British fleet under Vice-admiral Sir Robert Calder. At the ensuing Battle of Cape Finisterre, Calder captured two Spanish ships but failed to inflict a decisive blow on Villeneuve's squadron, which later sailed to Cádiz, Spain's principal Atlantic seaport. Nelson arrived shortly afterwards and initiated a blockade of the port.
On 21 October 1805, Villeneuve's combined Franco-Spanish fleet sailed from Cádiz and was intercepted by Nelson, resulting in the Battle of Trafalgar. Although Nelson was killed at the height of the battle, his squadron inflicted a devastating defeat on the combined fleet, capturing or destroying 17 French or Spanish ships, including Villeneuve's flagship. The battered remnants of the French Mediterranean and Spanish Atlantic fleets retreated to Cádiz, although four French ships fled north and were intercepted and captured at the Battle of Cape Ortegal two weeks later. In total, the campaign cost Napoleon 13 French and 12 Spanish ships, eliminating any possibility of even regional superiority at sea and therefore preventing the planned invasion of Britain, which had already been indefinitely postponed. The elimination of the French and Spanish fleets and the end of the threat of French invasion was widely celebrated in Britain, and seen by First Lord of the Admiralty Lord Barham, as an opportunity to reduce costs and damage to his ships by withdrawing the Atlantic blockade to Britain during the winter under the assumption that the battered French Navy would be unable and unwilling to operate at sea during the period. He wrote: "It is of little purpose now, to wear out our ships in a fruitless blockade during the winter."
French plans
Barham had seriously miscalculated the strength of the Brest fleet, which had been uninvolved in the campaign of 1805 and was therefore at full strength. He also underestimated Napoleon, who had observed that Villeneuve's brief stay in the Caribbean had acted as a major threat to British trade, delaying convoys and causing panic among the West Indian merchants. The French naval authorities were also inspired by the effect of a raiding squadron under Counter-admiral Zacharie Allemand, which had escaped from Rochefort on 17 July 1805, caused significant disruption to British trade in the Atlantic and remained at sea off the North African coast. Seeking to repeat these effects, in November 1805 Napoleon ordered the commander at Brest, Vice-admiral Honoré Joseph Antoine Ganteaume, to prepare two strong squadrons for service in the Atlantic. These were to leave Brest under cover of darkness on 13 December, sail deep into the Atlantic and intercept any merchant convoys that they encountered. Subsequently, the squadrons were to separate, with one going to the South Atlantic and the other to the Caribbean to cause as much disruption to British intercontinental trade as possible. The orders encouraged the squadron's commanders not to engage any Royal Navy force of equivalent size or larger to avoid the risk of being captured or destroyed.
Ganteaume selected 11 ships of the line for the operation, including the 120-gun Impérial. Chosen as Leissègues' flagship, Impérial was to sail for the Caribbean with four other ships of the line, two frigates and a corvette. Leissègues' squadron carried over 1,000 French soldiers to augment the garrison on Santo Domingo under General Jean-Louis Ferrand, and was then required to spend two months blockading Jamaica before cruising along the American Eastern Seaboard to Newfoundland, returning to France when food supplies ran low. The other squadron was given to Counter-admiral Jean-Baptiste Philibert Willaumez in Foudroyant, with orders to cruise the shipping lanes of the South Atlantic before sailing to the Leeward Islands, communicating with the French colonies of Martinique, Guadeloupe and Cayenne and blockading Barbados. When British opposition became too strong, he was to return to the South Atlantic off Saint Helena, also returning to France once food supplies ran low. His squadron consisted of six ships of the line, two frigates and two brigs, and included among its captains Jérôme Bonaparte, the Emperor's younger brother. Although both squadrons carried six months provisions, they were expected to capture more during their voyages and it was intended that their raiding operations should last as long as 14 months, causing severe indirect damage to the British economy by restricting the movement of trade.
December 1805
On 13 December 1805, with the majority of the British blockade squadron anchored in Cawsand Bay and the remainder driven far offshore by a winter gale, the French squadrons sailed from Brest into the Bay of Biscay unnoticed. Within two days they had passed nearly 500 nautical miles (930 km) into the Atlantic Ocean and had encountered a British merchant convoy, Willaumez detaching in pursuit. The convoy was sailing to Britain from Gibraltar, escorted by the 64-gun HMS Polyphemus under Captain Robert Redmill and the frigate HMS Sirius under Captain William Prowse. Heavily outnumbered, the convoy turned away and ran before the wind, Willaumez in close pursuit. Later in the day a second convoy appeared to the north, of 23 ships sailing from Cork to the Caribbean escorted by the frigates HMS Arethusa under Captain Charles Brisbane, HMS Boadicea under Captain John Maitland and the brig HMS Wasp. With Willaumez distracted, Leissègues ordered his squadron in pursuit.
Willaumez's ships captured a number of stragglers from Redmill's convoy and managed to isolate Sirius, which only just escaped after narrowly avoiding an unequal encounter with four French ships of the line. With the convoy dispersed, Willaumez gathered his scattered forces and despatched the frigate Volontaire to the Spanish island of Tenerife with the prizes, before turning the remainder of his squadron southwards for his designated cruising grounds. To the north, Leissègues gradually approached Brisbane's convoy during the night but did not close with him until the morning of 16 December. In response, Brisbane formed his three warships into a line of battle, accompanied by three of the larger merchant ships. This force could not hope to resist Leissègues' main force, but would enable the 17 other vessels to escape by blocking the French squadron's frigates from chasing them. Ignoring the escaping convoy, Leissègues formed his own line of battle and continued to close with Brisbane, whose faster ships steadily pulled away from the French throughout the day. As darkness fell, Leissègues abandoned the pursuit and turned to the south and Brisbane immediately despatched Boadicea to Brest and Wasp to the blockade squadrons along the Atlantic Seaboard with urgent warnings of the French operations in the Eastern Atlantic. Brisbane himself remained in distant contact with Leissègues for another day before the French squadron sheered away. Brisbane continued southwards with the remainder of his convoy, seeking the British blockade squadron at Cádiz.
Duckworth's cruise
On 20 November 1805, Allemand's squadron encountered a British convoy off the Savage Islands. Allemand's squadron was on its return journey to France when he encountered the convoy, consisting of six merchant ships sailing from Britain to Gorée under the escort of the brig HMS Lark under Commander Frederick Langford. Langford gave orders for his convoy to scatter as the French approached, Lark turning northwards in search of Rear-admiral Sir John Thomas Duckworth and the Cádiz squadron, reaching it on 26 November. Duckworth immediately sailed in pursuit of Allemand, leaving behind only two frigates to watch Cádiz in his absence.
Sailing south from Cádiz, Duckworth's squadron reached Madeira on 5 December, passing Tenerife ten days later without sighting any French ships. Continuing south to the Cape Verde Islands, Duckworth reluctantly conceded that the French squadron had escaped and he retired northwards until he encountered Brisbane's reduced convoy on 23 December. Tracking the presumed course of Leissègues' ships, Duckworth continued northwards on a course that would intercept the French squadron. At 06:45 on 25 December, at 30°52′N 20°16′W / 30.867°N 20.267°W, approximately 200 nautical miles (370 km) northwest of the Canary Islands, lookouts in Duckworth's squadron spotted nine sails in the distance. As Allemand's squadron was estimated to have approximately nine ships, Duckworth initially believed that his enemy was Allemand, possibly accompanied by prizes captured on his cruise. However, as he closed with the French, it became clear that this was a different squadron altogether. In fact his target was Willaumez, and despite the French admiral's efforts, Duckworth was steadily gaining on him, the ships of the line HMS Superb, HMS Spencer and HMS Agamemnon outstripping the rest of the British squadron.
By 13:00 on 26 December, the flagship Superb was just 7 nautical miles (13 km) behind the rearmost French ship, with Spencer 4 nautical miles (7.4 km) further back and Agamemnon another 5 nautical miles (9.3 km) distant. The rest of the squadron was more than 22 nautical miles (41 km) behind the leaders, almost completely out of sight, with the rearmost ship, HMS Donegal, more than 45 nautical miles (83 km) behind Superb. The more compact French squadron was therefore at an advantage. The British were too dispersed to be able to bring a powerful enough force to engage the French in equal battle and the distance between the individual British ships was too great to allow them to provide mutual support if Willaumez turned to face them. Therefore, to the fury of his officers, Duckworth called off the pursuit. This decision was heavily criticised, both at the time and subsequently: historian William James commenting that "had the Superb brought to action, as in the course of a few hours she might, the sternmost French ship . . . the issue, in all reasonable calculation, would have been favourable to the British". Captain of the flag ship, HMS Superb, Richard Goodwin Keats, having missed Trafalgar where he was to have been Nelson's second was keen for an engagement but makes no criticism of the decision when writing to Nelson's brother just a few days after the event.
Gathering his scattered squadron, Duckworth despatched the frigate HMS Amethyst to Britain with the news of the French activity in the Eastern Atlantic, his message suggesting that the French were probably destined for the Dutch East Indies. He himself turned southwest towards the Leeward Islands, where he could resupply his ships in preparation for resuming the blockade at Cádiz. On 2 January 1806 he ordered HMS Powerful under Captain Robert Plampin to sail for the Indian Ocean and reinforce the British squadron there, in case Willaumez's squadron reached Asian waters.