The Peninsular War: A Defining Conflict in the Napoleonic Era (1807–1814)

The Peninsular War, a pivotal military conflict, unfolded across the Iberian Peninsula from 1807 to 1814. It pitted the combined forces of Spain, Portugal, and the United Kingdom against the formidable invading and occupying armies of the First French Empire. This grueling struggle was an integral part of the broader Napoleonic Wars and is known in Spain as the Guerra de la Independencia Española, or Spanish War of Independence, highlighting its profound significance as a national struggle for sovereignty.

The conflict's genesis can be traced to the French and Spanish invasion and occupation of Portugal in 1807, initiated by the Treaty of Fontainebleau, which allowed French troops to transit through Spain. However, the situation dramatically escalated in 1808 when Napoleonic France, previously an ally of Spain, turned its attention to occupying Spanish territory itself. Napoleon Bonaparte, seeking to consolidate his control over Europe and enforce the Continental System against Great Britain, orchestrated the infamous abdications of King Ferdinand VII and his father, Charles IV, at Bayonne. He then controversially installed his own brother, Joseph Bonaparte, on the Spanish throne and promulgated the Bayonne Constitution, an imposed liberal charter that fundamentally challenged traditional Spanish governance.

The vast majority of Spaniards vehemently rejected this foreign imposition and the new monarch, igniting a ferocious and bloody war to expel the French. This protracted conflict endured until the Sixth Coalition ultimately defeated Napoleon in 1814. The Peninsular War is widely regarded as one of the very first wars of national liberation, setting a precedent for popular resistance movements. It is particularly significant for pioneering large-scale guerrilla warfare, a revolutionary approach to combat that severely hampered the French conventional forces.

Key Moments and Dynamics of the Peninsular War

The war in Spain officially commenced with the spontaneous and widespread Dos de Mayo Uprising in Madrid on 2 May 1808, a popular revolt against French occupation that rapidly spread across the country. It concluded on 17 April 1814, with the restoration of Ferdinand VII to the Spanish monarchy, signifying the reestablishment of the Bourbon dynasty.

• Breakdown of Spanish Administration: The French occupation utterly dismantled the existing Spanish administration, leading to its fragmentation into numerous, often quarreling, provincial juntas. While these juntas embodied local resistance, their disunity presented significant challenges for a unified war effort.
• A Costly Conflict: This period remains the bloodiest episode in Spain's modern history. In relative terms, accounting for population size, the Peninsular War's death toll was approximately double that of the Spanish Civil War of 1936-1939, underscoring its devastating human cost.
• The Cortes of Cádiz: In 1810, a reconstituted national government, known as the Cortes of Cádiz, formed in the secure port city of Cádiz, acting effectively as a government-in-exile. Despite being besieged by some 70,000 French troops, the Cortes managed to promulgate the liberal Spanish Constitution of 1812, a foundational document that later served as a cornerstone for European liberalism due to its emphasis on national sovereignty, separation of powers, and individual rights. However, its isolation prevented it from raising effective armies to directly confront the French.
• Strategic Importance of Portugal: British and Portuguese forces successfully secured Portugal, transforming it into a vital strategic base. From this relatively safe position, they launched successive campaigns against the French army in Spain and supplied the Spanish forces and guerrillas. This continuous pressure from conventional Allied armies, combined with the relentless harassment by Spanish irregular forces, effectively tied down vast numbers of Napoleon's troops.
• Combined Allied Strategy: By severely restricting French control over territory and disrupting their lines of communication, the combined allied forces—both regular Anglo-Portuguese armies and irregular Spanish guerrillas—prevented Napoleon's marshals from fully subduing the rebellious Spanish provinces. This unique synergy prolonged the war through years of a costly stalemate for the French.
• Wellington's Leadership: The British Army, under the brilliant command of Lieutenant General Sir Arthur Wellesley, later the 1st Duke of Wellington, played a crucial role in guarding Portugal and campaigning against the French in Spain. His strategic genius, famously demonstrated by the construction of the Lines of Torres Vedras which protected Lisbon, allowed Portugal to serve as an impregnable base.
• Reformed Portuguese Army: The previously demoralized Portuguese army underwent a comprehensive reorganization and refitting under the command of Lieutenant General William Beresford. Appointed commander-in-chief of the Portuguese forces by the exiled Portuguese royal family, Beresford transformed the army into a formidable fighting force that fought effectively as a vital component of the combined Anglo-Portuguese Army under Wellesley.

Turning Points and the French Retreat

A significant turning point in the Peninsular War occurred in 1812, largely influenced by events elsewhere in Europe. With Napoleon diverting a massive contingent of his Grande Armée for what proved to be a disastrous invasion of Russia, the French forces in the Iberian Peninsula were critically weakened and depleted.

• Allied Offensive (1812): Seizing this opportune moment, the combined allied army under Wellesley launched a vigorous offensive into Spain. They delivered a crushing defeat to the French at the Battle of Salamanca in July 1812, a decisive victory that allowed them to briefly occupy the Spanish capital, Madrid.
• Decisive Victory at Vitoria (1813): The following year, Wellesley secured another monumental and decisive victory over King Joseph Bonaparte's army in the Battle of Vitoria in June 1813. This battle effectively shattered French military presence in Spain and forced Joseph Bonaparte to flee.
• French Withdrawal: Relentlessly pursued by the combined armies of Britain, Spain, and Portugal, Marshal Jean-de-Dieu Soult, facing dwindling support and resources from an increasingly depleted France, led the exhausted and demoralized French forces in a fighting withdrawal across the Pyrenees during the harsh winter of 1813–1814, marking the end of significant French occupation in Spain.

The "Spanish Ulcer" and Lasting Legacy

The prolonged years of fighting in Spain exacted a catastrophic toll on France's Grande Armée. Despite often winning individual battles, the French were ultimately defeated by the nature of the conflict itself. Their communications and supply lines were severely stretched and constantly harassed, and their units were frequently isolated, attacked, or overwhelmed by the relentless partisan guerrilla warfare, characterized by constant raids, ambushes, and sabotage.

While the conventional Spanish armies were repeatedly beaten and forced to the peripheries, they would consistently regroup and relentlessly hound and demoralize French troops, preventing them from ever establishing full control. This continuous drain on French manpower and resources, estimated to have cost Napoleon hundreds of thousands of troops and immense financial strain, led Napoleon himself to famously dub the conflict the "Spanish Ulcer," recognizing its debilitating effect on his empire. He later reflected, "This cursed war was the cause of my misfortunes."

The war and the popular revolution against Napoleon's occupation had profound and lasting consequences for both Portugal and Spain:

• The Spanish Constitution of 1812: Promulgated by the Cortes of Cádiz, this groundbreaking constitution was a beacon of European liberalism, advocating for popular sovereignty, separation of powers, freedom of the press, and other individual rights. Though later repealed, its influence resonated throughout 19th-century liberal movements.
• Socio-Economic Devastation: The immense burden of war fundamentally destroyed the social and economic fabric of both Portugal and Spain. It ushered in an era of severe social turbulence, increased political instability, and prolonged economic stagnation due to widespread destruction, population loss, and immense debt.
• Post-War Civil Conflicts: The ideological divide forged during the war between liberal and absolutist factions, often led by officers trained in the Peninsular War, persisted for decades. This led to devastating civil wars across Iberia, notably in Spain (such as the Carlist Wars), continuing until around 1850.
• Independence of American Colonies: The cumulative crises and disruptions caused by the invasion, revolution, and subsequent restoration in the mother countries created a power vacuum and a unique opportunity for self-determination in the American colonies. This directly led to the independence of most of Spain's American colonies (e.g., Mexico, Gran Colombia, Argentina) and the independence of Brazil, which remained a monarchy after severing its ties with Portugal.

What was the primary cause of the Peninsular War?

The Peninsular War escalated due to Napoleon's direct intervention in Spanish dynastic affairs in 1808, installing his brother Joseph Bonaparte as king after forcing the abdications of the Spanish Bourbon monarchs. This act was preceded by the French invasion of Portugal in 1807, which allowed a large French military presence in the Iberian Peninsula.

Why is the Peninsular War considered significant for modern warfare?

It is considered one of the first wars of national liberation, demonstrating widespread popular resistance against an occupying force. Crucially, it popularized and showcased the effectiveness of large-scale guerrilla warfare (from the Spanish "guerrilla," meaning "little war"), a new form of irregular combat that severely hampered Napoleon's highly organized conventional army.

What was the "Spanish Ulcer"?

The "Spanish Ulcer" was Napoleon's own term for the Peninsular War. He used it to describe the constant drain of French resources, manpower, and morale that the conflict inflicted upon his empire, seeing it as a debilitating wound that offered no decisive victory but bled his Grande Armée dry.

What was the legacy of the Peninsular War for Spain and Portugal?

The war left both nations economically devastated, politically unstable, and deeply divided between liberal and absolutist factions, leading to decades of internal conflict. Critically, it also directly precipitated the independence movements in most of Spain's American colonies and Brazil.

The Battle of Corunna: A British Evacuation Under Fire (16 January 1809)

The Battle of Corunna, also known as A Coruña or La Corogne (and the Battle of Elviña in Spain), took place on 16 January 1809. This engagement saw a French corps led by Marshal of the Empire Jean de Dieu Soult launch an attack against a British army commanded by Lieutenant-General Sir John Moore. The battle was a critical moment within the broader Peninsular War, itself a part of the larger Napoleonic Wars.

This confrontation was the culmination of a significant French campaign led by Napoleon himself in late 1808. Following a series of defeats inflicted upon the Spanish armies by Napoleon, the British expeditionary force under Sir John Moore found itself in a precarious position. Moore had initially attempted a bold move to attack Soult's corps at Sahagún and divert the main French army, thereby relieving pressure on the retreating Spanish forces. However, facing an overwhelming French advance led by Napoleon, Moore was forced to abandon his offensive and initiate a rapid withdrawal towards the coast, with the strategic objective of evacuating his army by sea.

The Arduous Retreat to Corunna

The British army embarked on a grueling and infamous retreat across northern Spain, doggedly pursued by the French forces under Marshal Soult. During this desperate march, the British rearguard fought a series of fierce actions to fend off repeated French attacks, buying precious time for the main body of the army.

• Harsh Conditions: Both armies endured extreme hardship due to the brutal winter conditions, including severe cold, snow, and treacherous terrain. Supplies were scarce, and disease was rampant.
• Loss of Discipline: Much of the British army, battered by the retreat and lack of provisions, suffered a severe loss of order and discipline, with widespread straggling and desertion. A notable exception was the elite Light Brigade, under the command of Brigadier General Robert Craufurd, which maintained remarkable cohesion and discipline throughout the ordeal.
• Arrival at Corunna: When the exhausted British troops finally reached the port of Corunna, on the northern coast of Galicia in Spain, a few days ahead of their French pursuers, they faced a new crisis: their transport ships had not yet arrived. This left the army exposed and vulnerable with their backs to the sea.
• French Attack During Embarkation: After a torturous couple of days, the British fleet finally arrived. However, as the British forces were in the midst of the perilous process of embarking onto the ships, the French forces, having caught up, launched a direct attack. This forced the British to fight a full-scale battle to protect their evacuation and enable their departure for England.

Outcome and Legacy of the Battle

In the ensuing battle, the British army mounted a resolute defense, successfully holding off repeated French assaults until nightfall. With the cover of darkness, both armies disengaged. British forces immediately resumed their embarkation under extreme pressure, and the last transports managed to depart in the morning, even as they faced continued French cannon fire from the shore. While the strategic goal of evacuating the British army was achieved, the immediate territorial outcome saw the port cities of Corunna and Ferrol, along with much of northern Spain, captured and occupied by the French.

Tragically, during the fierce fighting, Sir John Moore, the brilliant and courageous British commander, was mortally wounded by a cannonball. He died shortly after the battle, having received the comforting news that his men had successfully repelled the French attacks and secured their escape. Moore's leadership throughout the retreat and at Corunna is widely regarded as having saved his army from annihilation, cementing his place as a hero in British military history. He was famously buried on the ramparts of Corunna, looking out to sea, a poignant symbol of the British sacrifices in the Peninsular War.