With the French and their Spanish allies preparing to invade England, only the wooden walls of the British navy stood in their way. The destruction of the enemy's fleet at Trafalgar forced Napoleon to abandon the plan.
In 1805, Napoleon's French Empire was the dominant land power in Europe, while the British Royal Navy controlled the seas. The British operated a blockade on French ports, restricting imports and trade and preventing French warships from leaving port. Britain had been at war with France again since the breakdown of the peace treaty of Amiens in 1803 and stood alone, protected by the English Channel and her navy. Napoleon's actions in carving up the German states and crowning himself King of Italy caused much concern in Europe and resulted in Russia, Portugal, Austria and others to form what became known as the Third Coalition and to declare war on France.
Napoleon resolved to invade Britain, free the seas for French trade and defeat his troublesome neighbour, but knew that to be successful he would have to achieve control of the English Channel by destroying the Royal Navy. The bulk of his own fleet was based in Brest on the Brittany coast and Toulouse on the Mediterranean, plus a few smaller squadrons scattered along the French Atlantic coast. France and Spain were allies and the Spanish fleet based at Cadiz and Ferrol was also available.
His plan was for the French and Spanish fleets in the Mediterranean and Cadiz to break through the British blockade and meet in the Caribbean. Once united, they planned to return and assist the fleet in Brest to emerge from the blockade and together clear the English Channel of British ships and open the way for the invasion. His choice of leader of this vital task was somewhat limited as many of the more experienced French naval officers had been dismissed or executed during the revolution. The most senior commander available was Vice Admiral Villeneuve who was given command of the Mediterranean fleet and, managing to avoid the British blockade during a storm, set sail for the Caribbean to join up with his Spanish allies.
Villeneuve and his fleet returned from the Caribbean intending to break the British blockade of Brest and free the French ships stationed there. He was intercepted by a British squadron commanded by Vice Admiral Sir Robert Calder and during the ensuing engagement known as the Battle of Cape Finisterre; two of Villeneuve's ships were captured and, badly shaken by the encounter, he abandoned his attempt to reach Brest and retreated to Ferrol.
Napoleon was furious at this setback and on the 10th of August demanded that Villeneuve sail at once for Brest and carry out his orders. Villeneuve now had 33 ships of the line in his fleet and these, together with the 21 ships in Brest, plus a further squadron of 5 ships from the smaller ports, would outnumber the British fleet. Villeneuve, fearing that his movements were being watched by the British, disobeyed Napoleon's orders and sailed for Cadiz.
On the 15th of August, the commander of the British Channel Fleet, Lord Cornwallis, decided to detach 20 ships of the line from guarding the Channel to attack the French and Spanish in Cadiz. This force, commanded by Vice Admiral Calder arrived off Cadiz on 15th September and was joined on the 29th by Admiral Lord Nelson who took command of the force from his flagship HMS Victory.
Nelson, already a national hero through his victories at the Battle of the Nile and at Cap St Vincent, had spent his career fighting the French and had lost an arm and an eye in the process. Even Napoleon respected Nelson's leadership and kept a bust of the Admiral in his private quarters.
Napoleon meanwhile had ordered the construction of hundreds of landing barges and moved the Grand Armee to the Pas de Calais in preparation for the invasion, but with no sign of Villeneuve's fleet by the 26th of August, the troops broke camp and marched back to Germany, effectively ending all plans for the invasion.
Nelson sent a squadron of 8 frigates under the command of Captain Blackwood to keep watch on the harbour of Cadiz while the main fleet stood off some 50 miles from the coast hoping to lure the enemy fleet out where they could be in open battle.
By the 2nd October, Nelson's fleet were badly in need of provisioning and 5 ships of the line plus 1 frigate were sent to Gibraltar for supplies. These ships were later redirected for escort duty in the Mediterranean and would not be available to Nelson. He also lost the services of Vice Admiral Calder and his 98 gun flagship Prince of Wales, ordered home to face a court martial over his apparent lack of aggression during the Finisterre battle.
Other British ships continued to arrive however and by the 15th October, the fleet was up to strength with 27 ships of the line, plus 7 smaller vessels. Of these, Victory and two others carried 100 guns, four carried 98 guns, one of 80 guns, sixteen of 74 guns and three of 64 guns. Nelson also had four frigates of 38 guns, a 12 gun schooner and a 10 gun cutter. Villeneuve's fleet at anchor in Cadiz also had problems. The British blockade had made it difficult to resupply provisions already depleted by the dash from the Caribbean. Many of his ships were undermanned and few of the remaining crewmen were experienced seamen with most of the crew having to be taught basic seamanship and gunnery on the few occasions when they got to sea. Knowing that Nelson's fleet was in the area, Villeneuve was reluctant to leave port as were his captains who had held a vote and decided to stay in the harbour.
Nevertheless, on the 16th September, Napoleon ordered the combined fleet at Cadiz to put to sea as soon as possible and join with seven Spanish ships at Cartagena, from where they were to sail to Naples and land the soldiers they carried to reinforce his troops there. They were further ordered to engage any smaller squadrons of British ships encountered on the journey. Villeneuve and some of his captains were however, still unwilling to sail and dredged up many reasons why they should remain in harbour. On the 18th October, Villeneuve had a sudden change of heart and ordered the fleet to put to sea. This volte face was due to a letter received by Villeneuve informing him that Vice Admiral Francois Rosily had arrived in Madrid with orders from Napoleon to take over command of the combined fleet and the prospect of being dismissed and disgraced before the whole fleet was too much to bear. He resolved to sail before Rosily could reach Cadiz.
Villeneuve's fleet comprised 33 ships of the line, some of which were the largest in the world at the time. The Spanish contribution of 15 ships included one of 136 guns, two of 112 guns, and one of 100 guns. The remainder of the combined fleets comprised six of 80 guns, twenty two of 74 guns and one of 64 guns. The fleet also included five 40 gun frigates and two 18 gun brigs.