Napoleon's invasion of the United Kingdom
Part of theWar of the Third Coalition
Napoleon Distributing the Legion of Honour at the Camp of Boulogne Philippe-Auguste Hennequin, 1806
Date Planned from 1803 to 1805 Location English Channel Result Grande Armée redeployed into Central Europe Franco-Spanish fleetblocked Subsequent destruction of most of the Franco-Spanish fleet during theTrafalgar campaign Invasion plan abandoned
Belligerents
France  Batavian Republic Spain	United Kingdom
Commanders and leaders
Napoleon I Étienne Bruix Pierre Villeneuve Honoré Ganteaume Carel Hendrik Ver Huell	George III Horatio Nelson Robert Calder Cuthbert Collingwood
Strength
200,000 men	615,000 men
Casualties and losses
Unknown	Unknown

Napoleon's planned invasion of theUnited Kingdom at the start of theWar of the Third Coalition, although never carried out, was a major influence on British naval strategy and the fortification of the coast ofSouth East England. In 1796 the French had already tried toinvade Ireland in order to destabilise the United Kingdom or as a stepping-stone toGreat Britain. The first FrenchArmy of England had gathered on theChannel coast in 1798, but an invasion of England was sidelined by Napoleon's concentration on the campaigns inEgypt and againstAustria, and shelved in 1802 by thePeace of Amiens. Building on planning for mooted invasions under France'sancien régime in1744,1759, and1779, preparations began again in earnest soon after the outbreak of war in 1803, and were finally called off in 1805, before theBattle of Trafalgar.

From 1803 to 1805 a new army of 200,000 men, known as theArmée des côtes de l'Océan (Army of the Ocean Coasts) or theArmée d'Angleterre (Army of England), was gathered and trained at camps atBoulogne,Bruges, andMontreuil. A large "National Flotilla"^[1] of invasion barges was built in Channel ports along the coasts of France and theNetherlands (then under French domination as theBatavian Republic), all the way fromÉtaples toFlushing, and gathered at Boulogne. This flotilla was initially under the energetic command of AdmiralÉtienne Eustache Bruix, but he soon had to return toParis, where he died oftuberculosis in March 1805. The part of the flotilla built by theBatavian Navy was under the command of Vice-AdmiralCarel Hendrik Ver Huell. He moved the Batavian flotilla fromVlissingen to Boulogne, despiteBritish attempts to prevent this.

Port facilities at Boulogne were improved (even though its tides made it unsuitable for such a role) and forts built, whilst the discontent and boredom that often threatened to overflow among the waiting troops was allayed by constant training and frequent ceremonial visits by Napoleon himself (including the first ever awards of theLégion d'honneur).^[2] A medal was struck and atriumphal column erected at Boulogne to celebrate the invasion's anticipated success.^[3] However, when Napoleon ordered a large-scale test of the invasion craft despite choppy weather and against the advice of his naval commanders such as AdmiralCharles René Magon de Médine (commander of the flotilla's right wing), they were shown up as ill-designed for their task and, though Napoleon led rescue efforts in person, many men were lost.

Napoleon also seriously considered using a fleet of troop-carryingballoons as part of his proposed invasion force, and appointedSophie Blanchard as an air service chief, though she said the proposed aerial invasion would fail because of the winds.^[4] (France's first military balloon had been used in 1794 byJean-Marie Coutelle.)^[5] Though an aerial invasion proved a dead-end, the prospect of one captured the minds of the British print media and public.

These preparations were financed by theLouisiana Purchase of 1803, whereby France ceded her huge North American territories to theUnited States in return for a payment of 50 millionFrench francs ($11,250,000). The entire amount was spent on the projected invasion. The United States had partly funded the purchase by means of a loan fromBaring Brothers ofLondon, which essentially meant that a British bank was indirectly funding an invasion of the country.^[6][7]

For his planned subsidiary invasion ofIreland, Napoleon had formed anIrish Legion in 1803, to create an indigenous part of his 20,000-manCorps d'Irelande.

Though the fleet-test was unsuccessful, Britain continued to be on high alert with defences from invasion. With the flotilla and encampment at Boulogne visible from the south coast of England,Martello towers were built along the English coast to counter the invasion threat, and militias were raised. In the areas closest to France, new fortifications were built, and existing ones previously built to guard against the 1779 invasion were completed or improved.Dover Castle had tunnels added to garrison more troops; theDover Western Heights were constructed (with a Grand Shaft to deploy its troops from its hilltop site to sea level rapidly should there be a landing),^[8] and theRoyal Military Canal was cut to impede Napoleon's progress into England should he land onRomney Marsh. Unfounded rumours of a massive flat French invasion raft powered by windmills and paddle-wheels, a secretly-dug channel tunnel, and an invasion fleet of balloons, spread via the print media, as did caricatures ridiculing the prospect of invasion. Anaval raid on Boulogne was also carried out in October 1804, and British fleets continued to blockade the French and Spanish fleets that would be needed to maintain naval superiority long enough for a crossing.

Before the flotilla could cross, however, Napoleon had to gain naval control of theEnglish Channel – in his own words, "Let us be masters of the Channel for six hours and we are masters of the world." He envisaged doing this by having theBrest andToulon Franco–Spanish fleets break out from the British blockade (led at Brest byBaron Collingwood and at Toulon byLord Nelson), and then sail across the Atlantic to threaten theWest Indies. This, he hoped, would draw off theRoyal Navy force underWilliam Cornwallis defending theWestern Approaches. The Toulon and Brest fleets (under AdmiralsPierre-Charles Villeneuve andHonoré Joseph Antoine Ganteaume respectively) could then rendezvous atMartinique, quickly sail back across the Atlantic to Europe (losing both these pursuing British fleets en route), land a force in Ireland (as in the two French Revolutionary invasions of Ireland in1796 and1798) and, more importantly, defeat what parts of theChannel Fleet had remained in the Channel, take control of the Channel, and defend and transport the invasion force, all before the pursuing fleets could return to stop them.

This plan was typical of Napoleon in its dash and reliance on fast movement and surprise, but such a style was more suited to land than to sea warfare, with the vagaries of tide and wind and the effective British blockade making it ever more impractical and unlikely to succeed as time passed. Only the Toulon force eventually broke out (on 29 March 1805) and, though it managed to cross the Atlantic, it did not find the Brest fleet at the rendezvous and so sailed back to Europe alone, where it was met by the force blockadingRochefort andFerrol (where invasion vessels had been prepared), was defeated at theBattle of Cape Finisterre, and forced back into port. Therefore, on 27 August 1805, Napoleon used the invasion army as the core of the newGrande Armée and had it break camp and march eastwards to begin theUlm campaign. Thus, by the time of the Battle of Trafalgar on 21 October, the invasion had already been called off, and so this battle further guaranteed British control of the Channel rather than preventing the invasion. The comment attributed toFirst Lord of the AdmiraltyLord St. Vincent – "I do not say they [the French] cannot come – I only say they cannot come by sea" – had been proved right.^[9]

Today, the Boulogne camp's site is marked by a 53 metres (174 ft) highcolumn (the tallest of such columns in France), built in the 1850s, with a statue of Napoleon on top, panels on the base showing him presenting medals of theLégion d'honneur to his troops and surrounded by railings decorated with the goldenFrench Imperial Eagle. The arsenal from the camp is also preserved.

• 
  Disposition of the French flotilla
• 
  The rumoured French invasion raft
• 
  Caricature mocking the fragile landing rafts
• 
  John Bull protected by theRoyal Navy
• 
  John Bull vanquishing Napoleon
• 
  Caricature of a "Gentle Salute" from the British Lion, knocking Napoleon's hat off (circa 1803)

• Charles François Dumouriez#Later life and death
• French intervention during the Irish Rebellion of 1798
• Operation Sea Lion,Adolf Hitler's planned invasion of the United Kingdom duringWorld War II

• Invasion of Britain –National Maritime Museum
• Objects related to the invasion in the NMM collections
• Anti-Napoleon Caricature and Propaganda in England 1798–1803
• Napoleon's views on the invasion of Britain
• Media related toNapoleon's planned invasion of the United Kingdom at Wikimedia Commons

• Napoleon's planned invasion of the United Kingdom
• 19th-century conflicts
• Cancelled military operations involving France
• Military history of the Pas-de-Calais
• 1800s in the United Kingdom
• War of the Third Coalition
• Second Hundred Years' War
• Cancelled invasions
• Military history of the Batavian Republic
• Invasions by France

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