Napoleon’s Invasion of England
Between 1803 to 1805, Napoleon Bonaparte assembled and trained an army of 200,000 men near Boulogne, named the “Army of England” for its intended purpose of invading and conquering that country, and had built a large flotilla of barges to ferry it across. Control of the English Channel during the crossing was a prerequisite for launching the invasion – as Napoleon put it: “Let us be masters of the English Channel for six hours, and we shall be masters of the world” – but that was no easy task, given the Royal Navy’s superiority over Napoleon’s Franco-Spanish navy.
While the Army of England was drilled, trained, and honed to a fine edge across the narrow waters separating it from its target, Napoleon’s admirals tried to wrest temporary naval control over the English Channel to secure a safe crossing. The Franco-Spanish navy was divided into two main contingents, penned in and blockaded by two powerful Royal Navy fleets in Toulon and Brest. A third British fleet guarded the English Channel. The Royal Navy’s confidence was such that the First Lord of the Admiralty commented in response to invasion fears that: “I do not say they cannot come – I say they cannot come by sea“.
Napoleon’s admirals had to break out of their blockade in Toulon and Brest, combine the newly freed fleets, then fall upon and defeat the Britsh Channel fleet, or at least ward it off of a stretch of the English Channel long enough for the invasion force to cross the waters to England. To that end, a plan was hatched for the Franco-Spanish fleets in Brest and Toulon to  slip past the British,  sail to the Caribbean, [3 ] elude the pursuing British and ditch them somewhere in the Caribbean,  link up and unite forces near Martinique,  sail the fleet, whose combined strength should now be stronger than that British fleet guarding England, to the English Channel, and  establish temporary naval superiority over the English Channel long enough to safely transport Napoleon’s army to England.
It was an ambitious plan, the kind that Napoleon liked with rapid movements that trick a superior enemy into a reaction that leaves his forces dispersed, providing an opportunity for a sudden concentration against part of the enemy’s forces. However, that was easier done on land, where a general could estimate marching times over known distances with enough accuracy to concentrate at an opportune time and place. It did not work as well for naval operations during the age of sail, because the vagaries of wind and weather made it difficult to time a concentration of fleets with precision.
As the plan worked out in practice, the Toulon fleet broke out of its blockade in March, 1805, eluded the British fleet commanded by Horatio Nelson, and raced to the Caribbean. In the Caribbean, it managed to lose and ditch the pursuing Nelson, then sailed to the rendezvous off Martinique to link up with the Brest fleet. However, it was stood up, because the other fleet failed to breakout and was still blockaded in Brest, and so it sailed back to Europe. Off Spain, it was defeated in the Battle of Cape Finisterre in July, 1805, and was forced to flee to Cadiz, where it was blockaded.
With the plan to control the English Channel in tatters, Napoleon gave up on the invasion, and in August 1805, transformed the finely trained Army of England into the Grande Armee, and marched it from the Channel coast to Central Europe to fight the Austrians and Russians. Months later, the Franco-Spanish fleet was defeated decisively at the Battle of Trafalgar, but by then the army that had trained for years to invade England was fighting in Central Europe, hundreds of miles from the English Channel.