Peninsular War 1808–1814: Wellington, Spain, Portugal & Complete Campaign Guide

The Peninsular War was where Wellington learned how to beat French armies repeatedly—and where Napoleon's empire discovered how expensive occupation could become.

From 1808 to 1814, British, Portuguese and Spanish forces fought French armies across the Iberian Peninsula. It was conventional war, siege war and guerrilla war at the same time.

How the war began

French troops entered Portugal in 1807 and then occupied key positions in Spain. Napoleon forced the Spanish Bourbon monarchs to abdicate and installed his brother Joseph as king.

The political shock triggered uprisings across Spain. French armies now faced both regular opponents and widespread local resistance.

Britain returns to the continent

Arthur Wellesley landed in Portugal in 1808 and won at Roliça and Vimeiro. The controversial Convention of Cintra allowed the defeated French army to evacuate Portugal, temporarily removing Wellesley from command.

Corunna and survival

Sir John Moore's army marched into Spain and then retreated before superior French forces. Moore was killed at Corunna in January 1809, but the army escaped by sea.

Wellesley comes back

Returning in 1809, Wellesley fought at Talavera and then concentrated on defending Portugal. His most important defensive achievement was not a single battle.

Lines of Torres Vedras

A vast fortified system north of Lisbon denied Marshal Masséna a decisive attack and stripped the French advance of supplies. When the French reached the lines in 1810, they found a position they could neither storm easily nor bypass.

From defence to offensive

As French strength weakened, allied armies moved back into Spain. Ciudad Rodrigo and Badajoz fell after bloody sieges in 1812.

Salamanca

At Salamanca in July 1812, Wellesley exploited a French movement that exposed part of Marmont's army. A rapid allied attack rolled up the French line.

The battle demonstrated Wellesley's ability to shift instantly from defensive patience to offensive decision.

Vitoria, 1813

The allied advance culminated in victory at Vitoria. Joseph Bonaparte's army was driven from its position and French rule in Spain effectively collapsed.

Across the Pyrenees

The war continued into southern France. Allied troops crossed the frontier and fought through the Pyrenees, Nivelle, Nive, Orthez and Toulouse before Napoleon's first abdication.

Guerrilla warfare

Spanish guerrillas attacked communications, isolated garrisons and forced the French to disperse troops. They did not win the war alone, but they made occupation expensive and complicated every French attempt to concentrate force.

The dark side

The campaign involved atrocities by all sides, brutal sieges and widespread civilian suffering. The sack of Badajoz by victorious allied troops is part of the history and cannot be removed from a celebratory Wellington narrative.

Related Regimental Record

• Duke of Wellington
• French Revolution
• Waterloo 1815

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The Spanish uprising and the French occupation problem

Napoleon could defeat armies more easily than he could make the occupation politically legitimate. The removal of the Spanish Bourbons and installation of Joseph Bonaparte triggered uprisings that forced French troops to disperse across cities, roads and garrisons.

Every detached battalion guarding communications was a battalion unavailable for concentration against the Anglo-Portuguese field army.

Portugal as the secure base

British strategy worked because Portugal became more than a place to land troops. The Portuguese army was reorganised under William Beresford, British money and naval access supported logistics, and Lisbon provided a secure strategic base tied to the Atlantic.

Wellington could retreat toward supply and shipping. French armies advancing into Portugal moved away from their own depots and into increasingly stripped country.

The Lines of Torres Vedras

The fortified lines north of Lisbon were built in secrecy as a system of redoubts, roads, signals and obstacles rather than one continuous wall. They exploited hills and choke points to make direct attack costly while allowing defenders to shift reserves.

The surrounding scorched-earth policy denied Masséna's army local food. The French reached the position but could neither force it nor sustain themselves indefinitely. Withdrawal became unavoidable.

Ciudad Rodrigo and Badajoz

The move from defence to offensive required capturing frontier fortresses. Ciudad Rodrigo fell quickly in January 1812. Badajoz in April was far bloodier. Allied troops stormed breaches under heavy fire and suffered severe casualties.

After the capture, widespread looting and violence by allied soldiers became one of the darkest episodes of the campaign. Any account of Wellington's victories that ignores Badajoz's sack is incomplete.

Salamanca: opportunity seized

Marshal Marmont attempted to extend around Wellington's flank. The movement stretched parts of the French army and created a temporary gap. Wellington recognised the opportunity and ordered an immediate attack.

The speed of this decision is why Salamanca matters. Wellington's reputation for defensive positions can hide his willingness to attack aggressively when an opponent exposed itself.

Vitoria and the collapse of Joseph's position

In 1813 the allies advanced through northern Spain. At Vitoria, multiple columns threatened French routes and the army of Joseph Bonaparte lost control of the battlefield and much of its baggage.

The victory was strategically decisive even though allied troops became distracted by captured wagons and loot, limiting pursuit.

Guerrillas and intelligence

Spanish guerrilla bands attacked couriers, convoys and isolated posts. Their contribution varied enormously by region and group. They were not one centrally controlled resistance army.

Their strategic effect came from forcing France to spend manpower protecting movement and from providing local intelligence and political pressure that made occupation increasingly expensive.

Coalition command

Wellington commanded British, Portuguese and Spanish forces whose governments had different priorities and whose units varied in training and supply. Managing that coalition was as important as battlefield tactics.

The Portuguese army in particular became a highly effective component of the field force. Describing the campaign as purely British erases one of its central military facts.

What the Peninsular War did to Napoleon

France had to maintain hundreds of thousands of troops across the Iberian theatre over time, although exact totals fluctuated dramatically. The war consumed experienced officers, horses, money and attention while Napoleon fought elsewhere.

It did not single-handedly defeat the empire, but it created a persistent strategic drain and gave Britain the continental army that later entered southern France—and supplied Wellington with the command experience he brought to 1815.

Sources & further reading

• Wellington's dispatches.
• Charles Oman, A History of the Peninsular War, used alongside newer scholarship.
• Spanish, Portuguese and French campaign records and memoirs.