Orders and weather made Trafalgar possible

Trafalgar need not have occurred when or as it did. Leaving the allied fleet at Cadiz through the winter would have forced Britain to sustain two Atlantic blockades and preserved options for the following spring. Instead Napoleon sent Admiral Rosily to replace Villeneuve, while news of Louis's squadron at Gibraltar encouraged Villeneuve to sail before the replacement arrived. Weather, supply orders, personal honor, and message timing all affected which ships were present. The resulting strategy was a chain of decisions and contingencies rather than an inevitable march toward Nelson's victory.