Peninsular War, (1808–14), that part of the Napoleonic Wars fought in the Iberian Peninsula, where the French were opposed by British, Spanish, and Portuguese forces. Napoleon’s peninsula struggle contributed considerably to his eventual downfall; but until 1813 the conflict in Spain and Portugal, though costly, exercised only an indirect effect upon the progress of French affairs in central and eastern Europe. The war in the Peninsula did interest the British, because their army made no other important contribution to the war on the continent between 1793 and 1814; the war, too, made the fortunes of the British commander Arthur Wellesley, afterward duke of Wellington.
Napoleon’s pact with Russia at Tilsit (July 7, 1807) left him free to turn his attention toward Britain and toward Sweden and Portugal, the two powers that remained allied or friendly to Britain. Russia, it was decided, would deal with Sweden, while Napoleon, allied to Spain since 1796, summoned (July 19) the Portuguese “to close their ports to the British and declare war on Britain.” His intention was to complete the Continental System designed to make economic war against Britain, for there was no other means to bring it to seek peace than by striking at its trade. When the Portuguese proved dilatory, Napoleon ordered General Andoche Junot, with a force of 30,000, to march through Spain to Portugal (October–November 1807). The Portuguese royal family fled, sailing to Brazil, and Junot arrived in Lisbon on November 30. The French army that conquered Portugal, however, also occupied parts of northern Spain; and Napoleon, whose intentions were now becoming clear, claimed all of Portugal and certain provinces of northern Spain. Unable to organize government resistance, the Spanish minister Godoy persuaded his king, Charles IV, to imitate the Portuguese royal family and escape to South America. The journey from Madrid was halted at Aranjuez, where a revolt organized by the “Fernandista” faction (March 17, 1808) procured the dismissal of Godoy and the abdication of Charles IV in favour of his son Ferdinand VII. Napoleon, taking advantage of the situation, sent in General Joachim Murat to occupy Madrid and, by a mixture of threats and promises, induced both Charles and Ferdinand to proceed to Bayonne for conferences. There, on May 5, 1808, Napoleon forced Ferdinand to abdicate in favour of Charles and Charles in favour of himself. In exchange, Napoleon promised that Spain should remain Roman Catholic and independent, under a ruler whom he would name. He chose his brother Joseph Bonaparte. On May 2, however, the people of Madrid had already risen against the invader, and the war for Spanish independence had begun.
The rebellion in Madrid began the movement that ultimately proved fatal to Napoleon’s power. Although the Madrid revolt was ruthlessly suppressed by the French, provincial insurrections took place thoroughout Spain, and the Spaniards showed great capacity for guerrilla warfare. The French were repulsed from Valencia, and General Pierre Dupont, who had advanced into Andalusia, was compelled to retreat and ultimately to capitulate with all his army at Bailén (July 23). The Spaniards now advanced upon the capital and expelled Joseph Bonaparte (August).
The French counterattack, leading to the recapture of Madrid (December 1808), forced the junta to retreat southward to Sevilla (Seville). In January 1810 General Nicolas de Dieu Soult began the conquest of Andalusia, and, with the fall of Sevilla in the same month, the central junta fled to Càdiz. Only the obstinate resistance of Wellington in Portugal, the continuous activity of the guerrillas, and dissensions among the French saved the peninsula from final submission. Indeed, the British forces, which had first landed in Portugal on August 1, 1808, quickly achieved some successes, conquering Lisbon and forcing the evacuation of the French from Portugal (Convention of Cintra, August 30, 1808). In 1809 the French returned to Portugal, briefly holding Oporto and Lisbon; but Wellington, with some difficulties, was able to outflank them and lead a force toward Madrid. His victory at the Battle of Talavera (July 27–28, 1809) was short-lived, nevertheless, and he was compelled to retreat to central Portugal, where he fortified himself within the country around Lisbon, now again under British rule. His celebrated “lines of Torres Vedras” were defensive works designed to resist any army that Napoleon could send against them.
For the next two years the battles and campaigns in various parts of Spain and Portugal, though numerous, were inconclusive. They did, however, wear down the resources of the French, in both men (now numbering more than 200,000) and matériel; and, when Napoleon in 1811–12 directed his whole attention toward Russia, not only were the depleted peninsular armies not reinforced but as many as 30,000 men were withdrawn for the Grand Army marching east.
Thus, from his base in Portugal, which he had successfully defended, Wellington in 1812 began his gradual advance into Spain. His defeat of Marshal Jean-Baptiste Jourdan at the Battle of Vitoria on June 21, 1813, finally decided the issue in the peninsula. Joseph Bonaparte withdrew from Spain, and Wellington fought his way across the Pyrenees into France (August 1813). Napoleon, after his crushing defeat at Leipzig (October 16–19, 1813), recognized the impossibility of retaining his hold on Spain and released Ferdinand, who had been detained by the French at Valençay since his abdication in 1808. In March 1814 Ferdinand VII returned to Spain and the throne.