After Admiral Lord Nelson defeated the Franco-Spanish fleet at the battle of Trafalgar on 21 October 1805, four French frigates and the brig "Furet" took refuge at Cadiz, where they remained into February 1806. To try to lure them out, Vice-Admiral Cuthbert Collingwood pulled his ships-of-the-line ten leagues out to sea, leaving only "Hydra", under Captain George Mundy, and the brig-sloop in close blockade. On 23 February a strong easterly wind drove the British off their station, which led the French commander, Captain Louis-Charles-Auguste Delamarre de Lamellerie, to seize the opportunity to escape. On the evening of 26 February "Hydra" and "Moselle" were three leagues west of the Cadiz lighthouse when they sighted the French vessels. Mundy began firing rockets and alarm guns to alert Collingwood, while sailing parallel to the escaping French squadron. Mundy then sent Carden in "Moselle" to try to locate the British fleet. On the morning of 27 February "Moselle" reached Collingwood, who despatched three frigates to try to catch the French.