Napoleonic Wars
1803-1815
Napoleonic France fought changing European coalitions in a struggle shaped by mass armies, economic warfare, imperial ambition, and resistance to French rule. Victories at Austerlitz and elsewhere created a continental empire, but the Peninsular War and invasion of Russia drained French power. Coalition forces entered Paris, and Napoleon's return ended with defeat at Waterloo.
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The Event
The Peace of Amiens briefly interrupted conflict between Britain and France, but disputes over commerce, strategic positions, and continental influence soon reopened war. Napoleon crowned himself emperor in 1804 and reorganized conquered territories after a series of decisive campaigns.
The settlement after Napoleon restored dynasties while retaining many administrative and legal changes. The wars redrew borders, spread nationalism, deepened state capacity, and established Britain as the leading maritime and financial power, while human losses and occupation burdens affected communities across Europe and beyond.
Key Moments
War Resumes after Amiens — May 18, 1803
Britain declared war on France after the breakdown of the Peace of Amiens. Both governments resumed preparations for a prolonged strategic and commercial struggle.
Napoleon Crowned Emperor — December 2, 1804
Napoleon crowned himself emperor in Paris in a ceremony attended by Pope Pius VII. The act consolidated a personal dynasty born from the revolutionary state.
Trafalgar and Austerlitz — December 2, 1805
Britain destroyed the combined French and Spanish fleet at Trafalgar in October, while Napoleon defeated Austrian and Russian armies at Austerlitz in December. The results divided maritime and continental supremacy.
Continental System — November 21, 1806
The Berlin Decree sought to exclude British goods from territories controlled by France and its allies. Smuggling, uneven enforcement, and economic costs weakened compliance.
Peninsular War Begins — May 2, 1808
Resistance to French occupation erupted in Spain and developed into a long war involving Spanish, Portuguese, British, and French forces. Guerrilla warfare and conventional campaigns tied down large French armies.
Invasion of Russia — June 24, 1812
Napoleon's multinational army crossed into the Russian Empire to compel renewed adherence to his continental policy. Retreat, combat, hunger, disease, and winter destroyed most of the invading force.
Coalition Enters Paris — March 31, 1814
Coalition armies entered Paris after advancing through Germany and France. Napoleon abdicated and was sent to Elba while the Bourbon monarchy was restored.
Defeat at Waterloo — June 18, 1815
Napoleon attacked the allied army under Wellington near Waterloo after returning from Elba. Prussian forces arrived during the battle, and the combined armies defeated the French.
Through the Lenses of International Relations Theory
Realism
War Resumes after Amiens
Amiens was a truce both governments used to rearm. Britain declined to leave Malta; Napoleon reorganised Italy and Switzerland and sent an expedition to the Caribbean. Neither had abandoned its aims, and peace between powers whose objectives are incompatible is not peace but an interval in which each prepares.
Napoleon Crowned Emperor
A crown converts a general into a dynasty, and a dynasty can be inherited, recognised and married into. Napoleon needed his regime to survive an assassination and to be treated as an equal by Vienna and Petersburg. The ceremony was an instrument of legitimacy, which is a resource like any other.
Trafalgar and Austerlitz
Six weeks separated the destruction of a fleet and the destruction of two armies, and the results cancelled. Britain could not be invaded; Austria and Russia could not hold central Europe. When each side is supreme in its own element the war does not end, it lengthens, and both had just guaranteed another decade.
Continental System
Unable to invade, Napoleon tried to bankrupt. It was a rational choice with a fatal requirement: it needed every coastline in Europe, which meant coercing states that had no quarrel with him. The policy generated the enemies that eventually destroyed it, first in Spain and then in Russia.
Peninsular War Begins
Napoleon deposed a friendly dynasty to install his brother, gaining nothing he did not already have and acquiring a war that consumed hundreds of thousands of men. It is the purest example in his career of appetite outrunning calculation, and he later named it as the cause of his ruin.
Invasion of Russia
Half a million men crossed the Niemen to compel a trading policy. Napoleon assumed Alexander would seek battle and then terms, as everyone had before, and he was right about the battle and wrong about the terms. The campaign rested on an assumption about the opponent rather than about capability.
Coalition Enters Paris
The coalition finally learned to avoid Napoleon and beat his marshals, and to keep fighting when he won. The Trachenberg plan was an admission that no army could defeat him directly, so they defeated everything around him. Numbers and persistence solved a problem that genius had made individually unsolvable.
Defeat at Waterloo
Napoleon returned because exile on Elba left him alive, near France and with a following, an obvious risk accepted for the sake of a merciful settlement. The Hundred Days is what leniency toward a defeated adversary can cost, and the second peace was correspondingly harsher.
Neorealism
War Resumes after Amiens
Britain's security required that no single power dominate the continent; France's required excluding Britain from Europe. Those conditions could not both hold, and neither state could reach the other. A naval power and a land power face a stalemate in which victory is unavailable and settlement unattractive, so the war ran twelve years.
Napoleon Crowned Emperor
Titles do not change capabilities, and the coalitions against France reformed regardless of what he called himself. What the coronation signalled was permanence, and permanence changes calculations: a France that would revert on Napoleon's death is a different problem from one whose position outlives him.
Trafalgar and Austerlitz
This is the elephant and the whale, and the phrase is not a joke. Land power and sea power generate capabilities that do not convert into one another, so neither pole could threaten the other's core. The system produced a durable bipolarity in which decisive victory was structurally unavailable.
Continental System
Economic warfare against a maritime hegemon required controlling the entire continental rim, which is an unbounded commitment. Each closure created a new smuggling route and a new reason to occupy somewhere else. Overextension was not a failure of execution; it was written into the strategy's requirements.
Peninsular War Begins
Spain converted Britain's maritime advantage into a continental foothold: a theatre reachable by sea, supplied by the navy, where French armies had to be fed by land. Wellington's army was small and permanent. Geography did the work, turning a peripheral front into a constant drain.
Invasion of Russia
Russia's advantages were structural and unbeatable: space to trade for time, a climate that punished any occupier, and a population large enough to absorb defeat. No tactical brilliance converts into victory against those conditions. Depth is a capability, and it is one France could neither match nor neutralise.
Coalition Enters Paris
What ended the empire was that everyone joined: Britain, Russia, Austria, Prussia, Sweden and eventually the German states. Bids for hegemony produce universal balancing if they last long enough, because the alternative for every remaining state is subordination. The coalition was the system correcting itself.
Defeat at Waterloo
He faced overwhelming and growing odds: two allied armies in Belgium and Austrian and Russian forces marching. Even a victory at Waterloo defers rather than reverses that. When the aggregate of a system is arrayed against one state, individual battles change the timetable and not the outcome.
Liberalism
War Resumes after Amiens
Britain fought on borrowed money, sustained by a parliament that voted taxes it could actually collect and a public that lent to its own government cheaply. That capacity was political rather than merely financial. A state whose creditors are its citizens can outlast one whose armies must pay for themselves by conquest.
Napoleon Crowned Emperor
The Revolution had abolished hereditary rank and now created a new nobility, a court and an imperial succession. The Civil Code's equality before the law survived; political liberty did not. It is possible to keep a revolution's legal achievements while discarding its self-government, and that is what happened.
Trafalgar and Austerlitz
Austerlitz destroyed the Third Coalition within months of its formation, and Pitt's government did not survive the news. Coalitions assembled by subsidy dissolve when the subsidised armies are beaten, because each member's domestic politics reasserts itself. Alliances of convenience have exactly the durability of the convenience.
Continental System
The system hurt the people expected to enforce it. French wine growers, Dutch merchants, Baltic timber ports and German cities all lost trade, and their governments found that subjects with commercial interests do not enforce laws that ruin them. Domestic resistance defeated the decree well before any army did.
Peninsular War Begins
Resistance came from juntas, provincial assemblies and eventually the Cortes of Cádiz, which wrote a liberal constitution while under siege. The war was fought in the name of a king who had abdicated, by people inventing popular sovereignty in his absence, and the constitution outlived the fighting as an idea.
Invasion of Russia
The Grande Armée was less than half French, drawn from Germans, Poles, Italians and others conscripted for someone else's purpose. Armies assembled without consent hold together while they are winning. In the retreat they disintegrated faster than the French units, and the empire's coalition dissolved with them.
Coalition Enters Paris
France was exhausted before it was defeated. Conscription had reached boys, the Senate turned on him, and Paris capitulated rather than be stormed. A regime resting on victory has no reserve of consent to draw on when victory stops, and its collapse is correspondingly sudden.
Defeat at Waterloo
Napoleon returned promising a liberal empire and issued the Additional Act, with an elected chamber and press freedom, because he could no longer rule on prestige alone. A regime that must offer a constitution to be accepted has already conceded the argument about consent, whatever happens in the field.
Neoliberalism
War Resumes after Amiens
Amiens contained no verification, no guarantor and no procedure for handling disputes about Malta or Piedmont. It recorded a moment of exhaustion and provided nothing for the moment after. Treaties without machinery last exactly as long as the convenience that produced them, which here was fourteen months.
Napoleon Crowned Emperor
The Concordat had already restored a working relationship with Rome, and the Pope's attendance cashed that arrangement in public. Napoleon took the crown from the altar and placed it himself, using the institution's authority while refusing its supremacy. Legitimacy was borrowed on carefully limited terms.
Trafalgar and Austerlitz
Britain's answer to losing on land was to buy allies, and it spent two decades doing so, paying tens of millions in subsidies to whoever would fight. That was a functioning system with treaties, schedules and audits. Finance was Britain's continental army, and it proved the more renewable resource.
Continental System
A blockade is a cartel, and cartels fail for the reason this one did: every member gains by cheating while the others comply. Napoleon could not monitor a coastline from Lisbon to Riga, and he sold exemption licences himself. Once the enforcer defects, the arrangement is finished.
Peninsular War Begins
Guerrilla war worked because it made French administration impossible rather than because it beat French armies. Couriers were intercepted, taxes uncollectable, garrisons blind. An occupier who cannot gather information or extract revenue is not governing, whatever the map shows about who holds the cities.
Invasion of Russia
Napoleon's system had always lived off the land, which works in dense, rich country and fails in a sparse one where the retreating enemy burns the stores. The invasion failed on logistics before it failed in battle, and operational skill does not compensate for an absent supply organisation.
Coalition Enters Paris
Chaumont, signed weeks earlier, bound the four powers to twenty years of alliance, fixed subsidies and no separate peace. That treaty is why the coalition did not fracture as five previous ones had. The commitment was written down, funded, and given a duration extending well beyond the war.
Defeat at Waterloo
The Congress powers declared him an outlaw within a week and reactivated Chaumont without renegotiating, each pledging a hundred and fifty thousand men. Standing arrangements are worth most in emergencies, because they remove the delay in which an opponent might act. The alliance responded faster than he could exploit.
English School
War Resumes after Amiens
Both governments published their cases, each accusing the other of violating the terms, each addressing an audience of European courts whose opinion still counted for something. The elaborate arguing over who had broken faith shows that obligation mattered even to states that had already decided to fight.
Napoleon Crowned Emperor
Europe's courts had to decide whether to recognise an emperor whose title came from a plebiscite and a self-coronation rather than from descent. Most eventually did, because the alternative was pretending France had no government. Recognition follows effective power far more reliably than it follows legitimacy.
Trafalgar and Austerlitz
Austerlitz was followed within months by the dismantling of the Holy Roman Empire, a framework a thousand years old abolished by a foreign victor. Whatever one thinks of that institution, its removal showed that the constitutional furniture of Europe now depended on battles rather than on custom.
Continental System
Both sides made war on neutral commerce, Britain by Orders in Council and France by decree, and the neutrals, principally the United States of America, were squeezed until they fought. The rights of neutrals were settled European practice, and this is where both great powers found them inconvenient.
Peninsular War Begins
The French treated resistance by men without uniforms as brigandage and executed accordingly; the Spanish treated occupation as an outrage against a legitimate crown. Neither category fitted, and Goya recorded the result. The customary limits of European warfare had no vocabulary for a population in arms.
Invasion of Russia
Moscow burned and neither side quite claimed it, each finding the destruction of a capital hard to own. Alexander refused to negotiate even with the enemy in his city, itself a departure from eighteenth-century practice. The conventions by which wars had been ended no longer applied.
Coalition Enters Paris
The allies entered Paris and did not sack it, declaring war on Napoleon rather than on France and inviting the French to choose a government. The restraint was calculated and it was also a claim: that a society of states was being restored, and that its members do not destroy each other's capitals.
Defeat at Waterloo
Declaring a head of state an outlaw beyond the protection of the law was a novelty, and the powers reached for it because their existing categories had none that fitted. It is an early instance of international society treating a ruler as personally illegitimate, an idea that returned much later.
Constructivism
War Resumes after Amiens
London saw a regime born in regicide that no agreement could bind; Paris saw a jealous commercial oligarchy financing other men's armies. Each picture made concession look like surrender to the party holding it. The war resumed partly because of what the two states believed the other was.
Napoleon Crowned Emperor
The ceremony borrowed from Charlemagne, from Rome and from the Bourbons at once, assembling a past for a regime that had none. That is what new states do. The imagery was not decoration but the substance of a claim about what France now was, addressed to Frenchmen and Europe together.
Trafalgar and Austerlitz
Nelson's death and Napoleon's sunrise both became national stories almost immediately, each country memorialising the half of the year it had won. Two societies drew opposite lessons about their own character from the same six weeks, and those self-images outlasted the strategic situation that produced them.
Continental System
The decrees described a Europe organised against England, and that description did real work: it gave conquest the appearance of a continental project rather than a French one. Where the framing was believed, cooperation followed. Where it was not, the same decrees read as occupation with a slogan attached.
Peninsular War Begins
The word guerrilla enters European languages here, and with it a new understanding of who may legitimately fight. A nation could resist without a state, an army or a king. That idea travelled far beyond Spain and has been used against occupiers, including Spain's own, ever since.
Invasion of Russia
Russia experienced this as a patriotic war, and the description created much of what it described: peasants, nobles and church acting for something called Russia. The invasion did more to constitute Russian national feeling than any policy of the state had managed, and it has been invoked in every war since.
Coalition Enters Paris
The powers were careful to say they fought a man and not a nation, which allowed France to be readmitted rather than dismembered. That framing was a choice with consequences: it made possible a settlement in which the defeated party sat at the table, and it shaped a century of European practice.
Defeat at Waterloo
Waterloo became a British national possession, a bridge and a station and a myth, while in France the defeat was recast almost immediately as tragedy rather than error. The same afternoon acquired two incompatible meanings, each politically useful, and both are still in circulation.