Trafalgar campaign
The Trafalgar campaign was a long and complicated series of fleet manoeuvres carried out by the combined French and Spanish fleets; and the opposing moves of the Royal Navy during much of 1805. These were the culmination of French plans to force a passage through the English Channel, and so achieve a successful invasion of the United Kingdom. The plans were extremely complicated and proved to be impractical. Much of the detail was due to the personal intervention of Napoleon, who as a soldier rather than a sailor failed to consider the effects of weather, difficulties in communication, and the strengths of the Royal Navy.
Despite limited successes in achieving some elements of the plan the French commanders were unable to follow the main objective through to execution. The campaign, which took place over thousands of miles of ocean, was marked by several naval engagements, most significantly at the Battle of Trafalgar on 21 October, where the combined fleet was decisively defeated, and from which the campaign takes its name. A final mopping up action at the Battle of Cape Ortegal on 4 November completed the destruction of the combined fleet, and secured the supremacy of the Royal Navy at sea.
French and British aims
had been planning an invasion of England for some time, with the first Army of England gathering on the Channel coast in 1798. Napoleon's concentration on campaigns in Egypt and Austria, and the Peace of Amiens caused these plans to be shelved in 1802. The resumption of hostilities in 1803 led to their revival, and forces were gathered outside Boulogne in large military camps in preparation for the assembling of the invasion flotilla. The Royal Navy was the main obstacle to a successful invasion, but Napoleon declared that his fleet need only be masters of the Channel for six hours and the crossing could be effected. Though the intended departure points were known and were being closely blockaded by the Royal Navy, First Lord of the Admiralty Lord Melville was short of ships. If a combined Franco-Spanish fleet were to force the Navy from its station for even a short while, the French invasion force might succeed in crossing unmolested. The French aimed to achieve at least temporary control of the Channel, while the British aimed to prevent this at all costs.Changing French plans
Napoleon proposed a total of four different strategies between July 1804 and March 1805, each with the object of collecting a large force of ships and moving up the Channel. Common elements included the decoying of some or all of the blockading Royal Navy fleets away from the Channel, the combining of the French fleets to lift the blockade of any ships that remained trapped in port, and the advancing of the fleet up the Channel to Boulogne, where they would escort the invasion force across.Plan I: July – September 1804
Napoleon's first plan, put forward in May 1804 for execution between July and September envisaged the break-out from Toulon of 10 ships of the line and 11 frigates under Admiral Latouche Tréville. They would evade the patrolling British fleet under Vice-Admiral Horatio Nelson and sail into the Atlantic, slipping past Alexander Cochrane's fleet off Ferrol and entering the Bay of Biscay. They would then make for Rochefort where they would be joined by another six ships of the line.While this was taking place Vice-Admiral Ganteaume would sail from Brest with 23 ships of the line and head out into the Atlantic, hopefully drawing the main British Channel Fleet under Admiral William Cornwallis after them. Latouche Tréville would then have a clear run into the Channel and up to Boulogne, where he would escort the invasion fleet safely across. The plan was complicated and depended on the unlikely events of favourable weather, the avoidance of Cochrane's and Nelson's fleets and the decoying away of Cornwallis. The plan was never put into operation. Latouche Tréville remained at Toulon rather than risk an encounter with Nelson, and died suddenly on 19 August, putting an end to the scheme.
Plan II: October 1804 – early 1805
The revised invasion plan after the death of Latouche Tréville was considerably more ambitious, and consisted of three distinct operations. Latouche Tréville's successor at Toulon, Vice-Admiral Pierre-Charles Villeneuve, would board 5,600 troops and sail his 10 ships of the line into the Mediterranean on 21 October. Having evaded Nelson he would collect the from Cádiz and pass through the Strait of Gibraltar, after which he would detach two ships carrying 1,800 troops. He would then head to the West Indies with the rest of his force, while the two detached ships were assigned to fulfil one of the three operations included in the plan.The two ships would sail to Saint Helena and capture the island from the British, before returning northwards to land at Senegal and stir up trouble in West Africa. Meanwhile, Rear-Admiral Édouard Thomas Burgues de Missiessy was to sail from Rochefort on 1 November with six ships of the line and 3,500 troops. Having evaded the British blockade he would sail to the West Indies, reinforce the French garrisons at Martinique and Guadeloupe and capture the British colonies of Dominica and St Lucia. Having achieved this Villeneuve and Missiessy would unite and combine forces, giving the French a fleet of 15 ships of the line and 5,000 men. With this force they would capture Surinam and raid other Dutch and British possessions, before sailing back across the Atlantic.
While this was taking place Ganteaume and his 21 ships of the line carrying 18,000 troops were to have sailed from Brest on 23 November, passed through the English Channel and into the North Sea, and then sailed around the coast of Scotland. They would arrive at Lough Swilly on the north coast of Ireland and land the troops. While a full-scale invasion of Ireland was under way Ganteaume would sail around the west coast of Ireland, arriving in the Western Approaches in time to meet Villeneuve and Missiessy's forces returning from the West Indies. With a combined force of nearly 40 ships of the line, the French would sweep up the Channel to Boulogne and effect the third and final part of the plan, the invasion of England. This plan, dependent on the weather, the non-interference of the British and subject to the vagaries of communication over thousands of miles of ocean verged on the impossible. The plan was never attempted, as the British intercepted the orders sent to Ganteaume, and the project was called off.
Plan III: January 1805
The strategic situation in Europe had altered considerably by January 1805. The Spanish had allied with France, but Napoleon was concerned about Austria and Russia, who appeared to be in negotiations with Britain. The danger of committing most of his forces across the Channel, from where they could not easily be recalled, had become clear to him. Should a combined Russian and Austrian force open a second front to the east, Napoleon would be hard pressed to deal with it. He decided to temporarily put his plans for invasion on hold, and developed a new strategy whereby his largely idle fleet could cause trouble for Britain. Villeneuve and Missiessy were ordered to embark troops and take their fleets to sea, where they would sail to the West Indies and attack the British possessions there. This would force the British to reallocate resources to defend them. Missiessy duly sailed from Rochefort on 11 January with five ships of the line, evaded Vice-Admiral Thomas Graves's blockading force and escaped into the Atlantic. Rear-Admiral Alexander Cochrane took his forces in pursuit, and both fleets sailed to the West Indies.File:Hennequin - Napoléon Ier distribue les croix de la légion d'honneur au camp de Boulogne le 16 août 1804.jpg|thumb|Napoleon Distributing the Legion of Honour at the Camp of Boulogne by Philippe-Auguste Hennequin
Villeneuve finally sailed from Toulon on 18 January, heading into the teeth of a gale. Their departure was noted by the patrolling British frigates and, who rushed to report the news to Nelson, anchored at La Maddalena. Nelson immediately rushed his fleet to sea, determining that considering the weather and the fact the French had embarked troops, that Villeneuve was heading east, perhaps to attack locations on the Italian coast, or the islands of Malta or Sardinia, or maybe even Greece or Egypt. He rushed south, hoping to intercept them south of Sardinia, but when they had not appeared by 25 January, he worried that he had missed them, and pressed further east, calling at Greece and then Alexandria on 7 February.
Finding no news of the French, he turned westward, calling at Malta on 19 February, where he received news that the French were back in Toulon. Villeneuve had in fact turned to port just two days after setting out, forced back by the weather and the inability of his ships and sailors to cope with it. The error of the frigates leaving the fleet unobserved when they had rushed to report to Nelson meant that he had spent nearly six weeks sailing back and forth across the Mediterranean through heavy seas while the French remained in port. A frustrated Nelson returned to resume the blockade.
Strategic situation in March 1805
The French Navy was largely confined to port, blockaded by various fleets and commands of the Royal Navy, while the main invasion force of 93,000 men in four Army corps waited in Boulogne. A combined French and Dutch squadron of nine ships of the line were quartered in the Netherlands, covered by Admiral Lord Keith's Downs squadron of 11 ships of the line. Neither squadron took part in the campaign. The main Channel Fleet, patrolling between Ushant and the Irish coast under Admiral William Cornwallis and his deputy Vice-Admiral Charles Cotton, consisted of 15 ships of the line, with detached squadrons of five ships of the line under Rear-Admiral Thomas Graves blockading Rochefort, and eight ships of the line under Vice-Admiral Robert Calder blockading Ferrol. They were maintaining a tight blockade over the French Atlantic forces, consisting of 21 ships of the line at Brest under Vice-Admiral Ganteaume, three or four ships of the line at Rochefort, and four French ships of the line under Rear-Admiral Gourdon and eight Spanish ships of the line under Admiral Grandallana at Ferrol.Six Spanish ships of the line and one French one were in port at Cádiz, under the watchful eyes of Rear-Admiral John Orde and his five ships of the line, with another six Spanish ships of line located at Cartagena under Admiral Salcedo. The French naval base at Toulon was home to 11 French ships of the line under Vice-Admiral Villeneuve, who was being kept bottled up by the 12 ships of the line of the Mediterranean Fleet under Vice-Admiral Horatio Nelson. Each commander had a number of frigates, sloops and brigs at their disposal. Further afield, Missiessy, pursued by Cochrane, sailed around the West Indies, but without making contact with each other. Napoleon recalled Missiessy once it became clear the Villeneuve had remained trapped in Toulon, and Missiessey began to voyage back to France on 28 March. March 1805 brought a significant development for Napoleon, an assurance from the Austrians that they did not plan to make war on France. Napoleon resolved to return to his scheme for the invasion of Britain, and drew up a new plan.