The Peninsular War: A Nation's Fight for Freedom Against Napoleonic Might

From 1807 to 1814, the Iberian Peninsula became a brutal battleground in a conflict known as the Peninsular War, a pivotal chapter within the larger Napoleonic Wars. This prolonged military struggle pitted the combined forces of Spain, Portugal, and the United Kingdom against the formidable invading and occupying armies of the First French Empire. In Spain, this tumultuous period is often inextricably linked with, or even considered synonymous with, their own War of Independence.

The Spark of Conflict and Napoleon's Gambit

The hostilities commenced in 1807 when French and Spanish armies, initially allies, transited through Spain to invade and occupy Portugal. However, the situation dramatically escalated the following year when Napoleonic France, demonstrating a ruthless ambition, turned on its erstwhile ally and occupied Spain itself. Emperor Napoleon Bonaparte, with characteristic boldness, engineered the forced abdications of both King Charles IV and his son Ferdinand VII, subsequently installing his brother, Joseph Bonaparte, upon the Spanish throne and promulgating the infamous Bayonne Constitution. This audacious move, however, gravely misjudged the spirit of the Spanish people. Most Spaniards vehemently rejected French rule, choosing instead to embark on a devastating, bloody war to expel the occupiers.

The Iberian Resistance and Allied Intervention

The war on the peninsula officially ignited in Spain with the fierce Dos de Mayo Uprising on May 2, 1808, a defiant act of rebellion that set the tone for years of intense struggle. The conflict would not conclude until April 17, 1814, marked by the eventual defeat of Napoleon by the Sixth Coalition and the restoration of Ferdinand VII to the Spanish monarchy. The initial French occupation crippled the existing Spanish administration, causing it to fragment into a collection of quarreling provincial juntas. This harrowing episode remains the bloodiest event in Spain's modern history, its relative toll on the population doubling that of the Spanish Civil War. A reconstituted national government, the Cortes of Cádiz, essentially functioning as a government-in-exile, managed to fortify itself in the secure port city of Cádiz in 1810. Despite this, it found itself besieged by some 70,000 French troops and struggled to raise effective armies.

Crucially, British and Portuguese forces eventually succeeded in securing Portugal, establishing it as a vital, safe base from which to launch sustained campaigns against the French army. From this strategic position, they also managed to funnel much-needed supplies to the Spanish resistance. Meanwhile, regular Spanish armies, alongside fiercely effective guerrilla fighters, skillfully tied down vast numbers of Napoleon's troops across the rugged terrain. By strategically restricting French control of territory, these combined allied forces, both regular and irregular, effectively prevented Napoleon's marshals from fully subduing the rebellious Spanish provinces, leading to years of grinding stalemate. The British Army, under the brilliant leadership of then Lt. Gen. Sir Arthur Wellesley (who would later become the iconic 1st Duke of Wellington), diligently guarded Portugal and campaigned extensively against the French in Spain. He fought alongside a reformed Portuguese army, which, though initially demoralized, was reorganized and expertly refitted under the command of Gen. William Beresford, appointed commander-in-chief by the exiled Portuguese royal family. This formidable Anglo-Portuguese Army under Wellesley became a linchpin of the allied effort.

The Turning Tide and French Burden

A significant turning point arrived in 1812. As Napoleon embarked on his disastrous invasion of Russia with a massive army, the combined allied forces under Wellesley seized the opportunity, pushing deep into Spain. They achieved a decisive victory over the French at Salamanca and triumphantly captured the capital, Madrid. The following year brought yet another pivotal moment with Wellesley's overwhelming victory against King Joseph Bonaparte's army in the Battle of Vitoria. Pursued relentlessly by the armies of Britain, Spain, and Portugal, Marshal Jean-de-Dieu Soult, facing dwindling support from a depleted France, led his exhausted and demoralized French forces in a grueling fighting withdrawal across the formidable Pyrenees mountains during the harsh winter of 1813–1814.

The years of bitter fighting in Spain proved to be an immense and unsustainable burden on France's Grande Armée. While the French often achieved tactical victories in battle, they were ultimately worn down and defeated by the relentless, protracted nature of the conflict. Their communications and supply lines were constantly stretched and severely tested, and their units frequently found themselves isolated, harassed, or completely overwhelmed by partisans waging an intense guerrilla war of raids and ambushes. The conventional Spanish armies, though repeatedly beaten and driven to the peripheries, possessed an indomitable spirit, regrouping consistently to relentlessly hound and demoralize the French troops. This continuous drain on French resources, a total war unwittingly provoked by Napoleon himself, famously led him to label the conflict the "Spanish Ulcer."

Lasting Legacy and Profound Impact

The war and revolutionary fervor against Napoleon's occupation culminated in the promulgation of the Spanish Constitution of 1812 by the Cortes of Cádiz, a landmark document that would later serve as a cornerstone of European liberalism. However, the immense burden of war utterly destroyed the social and economic fabric of both Portugal and Spain, ushering in an era of profound social turbulence, increased political instability, and prolonged economic stagnation. Devastating civil wars between liberal and absolutist factions, often led by officers hardened by their experiences in the Peninsular War, continued to plague Iberia well into 1850. The cumulative crises and disruptions caused by invasion, revolution, and subsequent restoration also had far-reaching consequences across the Atlantic, ultimately leading to the independence of most of Spain's American colonies and the eventual independence of Brazil, which, after severing ties with Portugal, notably remained a monarchy.

A Specific Engagement: The Battle of Medellín

Within this sprawling conflict, the Battle of Medellín, fought on March 28, 1809, stands as a notable engagement. In this instance, the French forces under Marshal Victor secured a victory against the Spanish under General Don Gregorio Garcia de la Cuesta. This battle marked the first major concerted effort by the French to occupy Southern Spain, a strategic objective largely completed with their subsequent victory at the Battle of Ocaña later that same year.