The Peninsular War was fought from 1808 to 1814 in Spain and Portugal, pitting the forces of Napoleon Bonaparte’s French Empire against the combined resistance of Spain, Portugal, and Britain. It was one of the longest and most costly campaigns of the entire Napoleonic period, producing more than 60 major battles and 30 major sieges over six years and resulting in enormous casualties on all sides. Napoleon himself later described Spain as his bleeding wound, the conflict that never healed and drained his empire of troops and resources throughout the critical later years of his reign. The war is historically significant for two reasons above all others. First, it was the first theater of the Napoleonic Wars in which France suffered a serious and sustained military reverse, eventually losing control of the Iberian Peninsula entirely. Second, it gave rise to the widespread use of guerrilla warfare as a military strategy, producing the very word guerrilla, from the Spanish for little war, that has been used ever since.
What Was the Napoleonic Era?
The Napoleonic Era refers to the period of French and European history dominated by Napoleon Bonaparte, lasting from his seizure of power in France in 1799 to his final defeat and exile in 1815. At the height of his power after the Treaties of Tilsit in 1807, Napoleon effectively controlled or dominated virtually the entire European continent. The Peninsular War was one of the first and most important signs that this dominance had limits, as France found itself unable to pacify a determined popular resistance supported by a professional British army. The war in Spain and Portugal ran alongside and interacted with other Napoleonic conflicts, overlapping with the War of the Fifth Coalition in 1809 and eventually merging with the War of the Sixth Coalition in 1813 and 1814 as Napoleon’s empire collapsed.
Peninsular War – Background and Causes
The origins of the Peninsular War lay in Napoleon’s determination to enforce the Continental System, his strategy of blockading Britain from European trade, and his increasingly high-handed treatment of Spain, which had been a French ally since 1796.
Portugal was the immediate trigger. Portugal had long-standing commercial and political ties with Britain and refused to join the Continental System and close its ports to British shipping. Napoleon pressured Spain, his ally, into allowing French forces to cross Spanish territory to invade Portugal. In November 1807, French forces under General Junot crossed into Portugal and occupied Lisbon. The Portuguese royal family fled to Brazil rather than submit, and Portugal came under French occupation.
However, the French presence in Spain itself quickly became the larger problem. Napoleon used the pretext of managing the occupation of Portugal to station large numbers of French troops across Spain, and in 1808 he moved to exploit a succession dispute within the Spanish royal family to seize control of Spain itself. He manipulated both King Charles IV and his son Ferdinand VII into surrendering their claims to the Spanish throne at a meeting in Bayonne, France, and in June 1808 placed his own brother Joseph Bonaparte on the Spanish throne as King Joseph I.
Napoleon badly misjudged the likely Spanish reaction. He expected the Spanish people to accept the change of dynasty as passively as other European peoples had accepted French reorganization of their governments. Instead, the imposition of a foreign king on Spain provoked a furious and widespread national uprising.
Peninsular War – The Spanish Uprising and the Battle of Bailen
The war began in earnest with the popular uprising in Madrid on May 2nd, 1808, known as the Dos de Mayo, when Spanish civilians and soldiers attacked French troops in the city. The French suppressed the Madrid uprising with great brutality, executing large numbers of those involved in the fighting, an event depicted in Francisco Goya’s famous paintings The Second of May 1808 and The Third of May 1808. However, the Madrid uprising triggered similar revolts across Spain, and within weeks virtually the entire country was in arms against the French.
The initial stages of the war produced a startling result. In July 1808, a Spanish army in Andalusia surrounded and forced the surrender of a French force under General Dupont at the Battle of Bailen. It was the first time in the Napoleonic Wars that a French army had been forced to capitulate in an open-field engagement, and it sent shockwaves across Europe. The news demonstrated that French forces were not invincible and emboldened resistance movements everywhere. The Spanish rebels forced Joseph Bonaparte out of Madrid in August 1808, temporarily restoring Spanish control of the capital.
Peninsular War – British Intervention and Wellington
Britain recognized immediately that the Spanish uprising offered a tremendous strategic opportunity. If France could be forced to tie down large numbers of troops in Spain and Portugal indefinitely, the strain on French resources and manpower would be enormous. Britain sent an army to Portugal in August 1808 under the command of Sir Arthur Wellesley, a highly capable general who had made his reputation in India. Wellesley defeated French forces at the Battle of Vimeiro in August 1808, the first British land victory of the Peninsular War.
Napoleon responded to the deteriorating situation in Spain by coming to the peninsula himself in late 1808, bringing a large army and rapidly restoring French control of most of the country. He drove the Spanish armies back, reoccupied Madrid in December 1808, and forced the British army under Sir John Moore to retreat northward to the coast at Corunna, where it was evacuated by sea in January 1809. Moore himself was killed during the rearguard action at Corunna. It appeared briefly as though France might successfully pacify Spain after all.
However, Wellesley returned to Portugal in April 1809, and from this point the British maintained a permanent military presence in the peninsula throughout the rest of the war. Wellesley, who was eventually elevated to the title of Duke of Wellington in recognition of his successes, proved a master of the defensive warfare that the Spanish theater demanded. He understood that his army was too small to defeat French forces in open battle while they could concentrate, so he chose his ground carefully, used the natural defensive features of the Portuguese landscape to his advantage, and constructed the famous Lines of Torres Vedras, an elaborate system of fortifications north of Lisbon, to make Portugal effectively impregnable to French attack. When French Marshal Massena invaded Portugal in 1810 with 65,000 men, he found the Torres Vedras lines impassable and was eventually forced to retreat in 1811, having lost large numbers of men to starvation and disease without achieving anything.
Peninsular War – Guerrilla Warfare
The most distinctive and historically significant feature of the Peninsular War was the widespread and highly effective use of guerrilla warfare by the Spanish population. When the regular Spanish armies were defeated by French forces in conventional battle, resistance did not stop but transformed into something the French found impossible to suppress. Bands of Spanish fighters ranging in size from a few dozen to several thousand men operated throughout the country, ambushing French patrols and supply convoys, attacking isolated garrisons, cutting communication lines, and making it impossible for French forces to move safely through much of the country except in large columns.
The guerrilla campaign imposed enormous costs on France. To keep the roads open, maintain supply lines, and protect their garrisons, the French were forced to tie down vast numbers of troops in purely defensive duties that contributed nothing to winning the war. Estimates suggest that at times France had 300,000 or more troops in Spain, yet could never concentrate enough of them in any one place to deliver a decisive blow to Wellington’s army or to finally suppress the guerrillas. The word guerrilla itself, derived from the Spanish for little war, entered the military vocabulary during this conflict and has remained in use ever since as a description of this style of irregular warfare.
The guerrilla campaign was brutal on both sides. The French responded to guerrilla attacks with severe reprisals against civilian populations, which further inflamed Spanish resistance rather than suppressing it. The atrocities of the war on all sides were documented in devastating artistic terms by Francisco Goya in his series of prints known as The Disasters of War, one of the most powerful anti-war artistic statements in the history of European art.
Peninsular War – The Allied Offensive and French Defeat
From 1812, the balance of the war shifted decisively against France. Napoleon’s catastrophic Russian campaign of 1812, in which the Grande Armee was effectively destroyed, forced him to withdraw experienced troops from Spain to rebuild his forces in Central Europe. Wellington seized the opportunity to go on the offensive. At the Battle of Salamanca on July 22nd, 1812, Wellington won a major victory over French Marshal Marmont, demonstrating that the Anglo-Portuguese army could defeat French forces in open battle as well as in defensive engagements. Wellington occupied Madrid briefly in August 1812, the second time in the war that the Spanish capital had been retaken from the French.
The decisive campaign came in 1813. Wellington advanced from Portugal with his Anglo-Portuguese army, coordinating with Spanish forces, and brought the main French army in Spain to battle at Vitoria on June 21st, 1813. The Battle of Vitoria was a complete French defeat. The French army broke and fled, abandoning enormous quantities of supplies, artillery, and treasure, including much of the personal baggage of King Joseph Bonaparte himself. The victory at Vitoria effectively ended French control of Spain. Wellington pursued the retreating French forces over the Pyrenees into France itself, winning several more engagements on French soil before Napoleon’s abdication in April 1814 ended the war.
Peninsular War – Significance
The significance of the Peninsular War in the history of the Napoleonic Era is considerable. Napoleon himself acknowledged that Spain was one of the principal causes of his downfall, describing it as the bleeding wound that never healed and comparing it to a running sore that gradually drained his empire of strength. The war tied down hundreds of thousands of French troops for six years at a time when they were desperately needed elsewhere, particularly after the Russian disaster of 1812 opened a new and even more demanding front.
The Peninsular War also marked a major development in the history of warfare. The guerrilla campaigns of the Spanish people demonstrated for the first time on a large scale that a conventional army could be defeated not by a rival conventional army but by the sustained irregular resistance of a motivated population. This lesson has been studied and applied by military commanders and resistance movements ever since.
Furthermore, the Peninsular War had important political consequences. The experience of fighting for national independence against French occupation stimulated Spanish and Portuguese nationalism and contributed to the independence movements that swept through Latin America in the years after 1814, as the example of popular resistance to foreign domination proved inspirational across the Atlantic. As such, the Peninsular War stands as one of the most consequential and distinctive conflicts of the Napoleonic Era, a war that helped determine the fate of Napoleon’s empire and left lasting marks on the military, political, and cultural history of Europe and the wider world.
