The weather took a turn for the worse in late summer of 1805, and the French Navy could not out maneuver the Royal Navy in order to allow the Napoleon’s invasion of England. When the War of the Third Coalition expanded, Napoleon’s Grande Armée marched east to defeat Russia and Austria. Nonetheless, the French fleet, under Admiral Pierre Charles Silvestre de Villeneuve, still needed to break Britain’s control of the seas. After Napoleon departed, Villeneuve sailed south to Cadiz, where his fleet combined with the Spanish ships of the line, then France’s ally. With the Franco/Spanish fleet, Villeneuve finally had the numbers to challenge the British who, pursuing Villeneuve, were conveniently awaiting them just over the horizon.

That fleet was led by one armed one eyed Vice Admiral Horatio Lord Nelson, already a household name in the British Empire for his victories against the French, Spanish, and Danes over the past 25 years. In the morning of 21 October 1805, Villeneuve sailed out of the Cadiz harbor with a favorable wind (relatively) to engage the British off of Cape Trafalgar. Upon sighting the 44 ships of the combined French and Spanish navies, Nelson sent off one last message to his fleet, “England expects that every man will do his duty” and then immediately attacked. His 33 ships sailed straight at the French and Spanish line in two columns, with his own ship, the 100 gun HMS Victory, leading the charge.

Villeneuve couldn’t believe what he saw and vowed to make Nelson pay for his audacity. The Holy Grail of fleet actions in the Age of Sail was to “cross the T” of an enemy fleet, i.e. to maneuver to a position where your ships could fire broadsides at a closing enemy who could only fire their bow, or forward, guns. The discrepancy in firepower inevitably led to the defeat of the fleet whose “T” was crossed. Moreover, a cannonball that penetrates the side of the ship usually only affects a few crew or guns, depending on the width of the ship. A cannonball that penetrates the bow (or stern) of a ship, causes great destruction along the entire length of the ship, affecting many more crew and guns in the process. The understrength British, outnumbered by a third, were exposing themselves to just such punishment by sailing directly at the broadsides of the combined Franco/Spanish fleet. The British were effectively crossing their own “T” against a numerically superior force. It was madness.

But crossing his own T was Nelson’s plan. He was gambling that the training and seamanship of the British sailors were superior to the gunnery of the French and Spanish sailors. Nelson believed his ships would not be exposed for too long before his men could bring their own broadsides to bear, and close with and board the French.

He was right.

As Villeneuve sailed north, Nelson’s ships sailed through the French fire, and though they took some damage without being able to reply in kind, they bisected and then isolated the southern half of the French fleet. Despite the French broadsides, he effectively crossed the French “T” but in this instance a lowercase “t”. Once the British were among the French and Spanish line, the British broadsides fell upon the sterns of the northern half of the combined fleet and the bows of the southern half. Furthermore, with this one bold stroke, the northern half was effectively taken out of the battle, as they had to fight the wind to turn around, and the southern half sailed directly into the teeth of the British cannon. This also effectively forced the southern half of Villeneuve’s fleet to sail directly into the British line where they could to be boarded by the British once they closed the distance.

As the northern half of the Franco/Spanish fleet sailed out of range, the British savaged the southern half. It took three hours of hard fighting but the issue was never in doubt. However, Nelson, being Nelson, was at the forefront of the battle. Around noon, his Victory was locked in a mortal struggle with the French ship Redoubtable. At 1:15pm while walking on the quarterdeck directing fire, he was shot by a French marine in Redoubtable’s rigging. He would live just long enough to learn of the confirmation of his decisive victory.

The British Isles were safe from invasion and the Royal Navy would be the undisputed master of the world’s oceans for the next one hundred years.