Napoleon's naval plan in 1805 was for the French and Spanish fleets in the Mediterranean and Cádiz to break through the blockade and combine in the West Indies. They would then return, assist the fleet in Brest to emerge from blockade, and in combination clear the English Channel of Royal Navy ships, ensuring a safe passage for the invasion barges. The plan seemed good on paper but as the war wore on, Napoleon's unfamiliarity with naval strategy and ill-advised naval commanders continued to haunt the French. The allied fleet, under the command of French Admiral Villeneuve, sailed from the port of Cádiz in the south of Spain on 18 October 1805. They encountered the British fleet under Admiral Lord Nelson, recently assembled to meet this threat, in the Atlantic Ocean along the southwest coast of Spain, off Cape Trafalgar. The Battle of Trafalgar was a naval engagement between the British Royal Navy and the combined fleets of the French and Spanish Navies during the War of the Third Coalition.