Marengo crossed the equator and on 13 March was in position . Atlantic campaign of 1806 Unknown to Linois, his squadron was sailing directly into the path of a major naval campaign, the Atlantic campaign of 1806. In the aftermath of the Battle of Trafalgar on 21 October 1805, and the subsequent end of the Trafalgar Campaign at the Battle of Cape Ortegal on 5 November 1805, the British had relaxed their blockade of the French Atlantic ports. French and Spanish losses had been so severe in the campaign that it was believed by the British First Lord of the Admiralty, Lord Barham, that the French Navy would be unable to respond in the following winter, and consequently withdrew most of the blockade fleet to Britain until the spring. This strategy miscalculated the strength of the French Brest fleet, which had not been engaged in the Trafalgar campaign and therefore was at full strength. Taking advantage of the absence of the British squadrons off his principal Atlantic port, Napoleon ordered two squadrons to put to sea on 15 December 1805. These forces were ordered to cruise the Atlantic shipping lanes in search of British merchant convoys and avoid confrontations with equivalent British forces. One squadron, under Vice-Admiral Corentin-Urbain Leissegues, was ordered to the Caribbean while the other, under Contre-Admiral Jean-Baptiste Willaumez, was ordered to the South Atlantic. Discovering on 24 December that the French squadrons had broken out of Brest, Barham despatched two squadrons in pursuit, led by Rear-Admiral Sir Richard Strachan and Rear-Admiral Sir John Borlase Warren. A third squadron detached from the blockade of Cadiz without orders, under its commander Rear-Admiral Sir John Thomas Duckworth, all three British forces cruising the mid-Atlantic in search of the French. Following a brief encounter with Willaumez, Duckworth sailed to the Caribbean and there discovered and destroyed Leissegues' squadron at the Battle of San Domingo in February 1806. With one of the French squadrons eliminated, Strachan and Warren remained in the mid-Atlantic anticipating Willaumez's return from his operations to the south. Warren's squadron was ordered to cruise in the Eastern Atlantic, in the region of the island of Madeira, directly across Linois's line of advance. Capture of Linois At 03:00 on 13 March 1806, lookouts on Marengo spotted sails in the distance to the southeast. Ignoring arguments from Bruilhac that the sails could be a British battle squadron, Linois insisted that they