<p>Fought between 1808 and 1814, the Peninsular War was one part of the larger <a href="https://www.thoughtco.com/french-revolutionary-and-napoleonic-wars-p2-1221702" data-type="internalLink" data-component="link" data-source="inlineLink" data-ordinal="1">Napoleonic Wars</a>, and was fought by Britain, France and Spanish loyalists against France and her allied troops. The conflict, dubbed the Spanish Ulcer, drained considerable resources away from Napoleon’s other efforts, and is known as the War of Independence in Spain.</p><h3>Origins of the Peninsular War</h3>By 1807, <a href="https://www.thoughtco.com/napoleon-bonaparte-biography-1221106" data-type="internalLink" data-component="link" data-source="inlineLink" data-ordinal="2">Napoleon</a> had quelled the powers of central and eastern Europe and remained – officially – in conflict with Britain, Sweden and Portugal. When Napoleon allied with Russia at Tilsit, they were tasked with tackling Sweden – an enemy of many centuries – while Napoleon himself turned to Western Europe. Portugal was a problem for Napoleon because they refused to take part in the <a href="https://www.thoughtco.com/the-continental-system-1221698" data-type="internalLink" data-component="link" data-source="inlineLink" data-ordinal="3">Continental System</a>, which the French Emperor used to squeeze Britain’s economy by barring them from any trade with the continent. Napoleon ordered Portugal to, not just bar Britain from using their ports, but declare war on Britain. The latter had been at war with France for years, and had been busy seizing continental possessions from its enemy.<p>Portugal opted not to follow these orders, and so a French force of 30,000 men and General Junot were dispatched in late 1807 to enforce matters. The Portuguese royals fled to Brazil, Junot occupied Portugal, and a Council of Regency asked the British for help. However, the French also occupied parts of Spain on their way through, and Napoleon claimed all of these areas as for the Empire; in actual fact, he wanted all of Spain, and soon had 100,000 troops in place. Members of the Spanish government were upset, and there’d already been infighting, including an alleged plot by the king’s heir leading to the latter’s arrest, and eventually King Charles IV was talked into fleeing like his Portuguese equivalents. However, his flight was halted, and in March 1808 he was forced to abdicate in favour of his son, Ferdinand VII, by the court.</p><p>Napoleon reacted by sending in more troops, and forced a conference between himself and the Spanish monarchs which resulted in Napoleon promising Spain would remain Roman Catholic and under an independent monarch if Charles and Ferdinand abdicated. They did, and Napoleon picked his brother <a href="https://www.thoughtco.com/napoleon-bonaparte-biography-1221106" data-type="internalLink" data-component="link" data-source="inlineLink" data-ordinal="4">Joseph</a> to rule. Napoleon believed he could wipe away Spain’s poor administration and weak government and found a strong, working system that could provide his empire with troops, money, and the end of British trade in the region.</p><h3>The War for Spain and Portugal</h3>Many Spanish didn’t accept this, and a revolt started on Dos de Mayo in Madrid. As this was crushed the revolt spread to other areas, fuelled by the church’s opposition to Napoleon, and workers fearing the Continental System. Saragossa held off a French attack, and Spanish forces beat back the French and forced Joseph to flee. However, the rebellion was as much a civil war than an anti-French crusade, between new and old, liberal and conservative, and sometimes rich verses poor. The French were a catalyst for a divided Spain to fragment and fight each other, as well as the French. Spain fractured into local juntas, and an attempt to organise a central junta was only partially successful. Napoleon sent more men, and forced the rebels back.<h3>The British Arrive and Falter</h3>By this point Britain had committed land forces in Portugal. They landed under Sir Arthur Wellesley (known later, and referred to from now on as the Duke of Wellington) in August 1808, and they liberated Lisbon and caused the French to leave the country thanks to victory against Junot at the Battle of Vimeiro, where 13,000 French fought 19,000 allies. However, when two new senior British commanders arrived, both outranking Wellington, they signed the Cintra Conventions which freed Junot’s army, and all three were later court-martialled for doing so. Wellington was the only one found not guilty. Meanwhile, in Andalusia 20,000 French under Dupont had been forced to surrender after 40,000 Spanish had surrounded them, the first such capture of a French army since the revolutionary wars. Other enemies of French took heart.<p>With Wellington busy clearing his name, Sir John Moore had taken charge of an increased British army in Portugal. Moore was assured of an alliance with Spanish forces, but after advancing he found himself isolated, if not outright lied to, and facing Napoleon himself, who had arrived to settle the issue. Madrid was taken by the French, and Moore’s army had to make a difficult retreat. Moore kept his army together, and the French were distracted, allowing some of the Spanish forces to survive. Napoleon felt victory was assured and, realising war was brewing in the east, left on January 1st 1809, planning to return if needed. Soult was supposed to finish off Moore, but was beaten at the Battle of Corunna, allowing nearly all of the British to evacuate the peninsular. Nearly all, because Moore was killed.</p><h3>Wellington Returns</h3>Given the dominance of the British Navy over the French, they were able to reorganise and land a new force, of which Wellington had managed to resume command. A new Portuguese army was also formed up under a British commander called Beresford. Wellington and Soult soon clashed as Wellington went after him in early 1809. Wellington beat the French at Oporto, which temporarily freed Portugal, and the British tried once more to enter Spain and work with the Spanish. As before the Spanish regulars were a divided and confused force, and plans were hampered by allied commanders, but Wellington managed to win a victory at Talavera against Joseph and Marshall Jourdain. However, the allied advance was halted, Wellington was despairing of the Spanish alliance, and with Soult threatening his retreat he returned to Portugal. Anglo-Spanish relations were in trouble. The Spanish army now suffered more defeats, and Wellington ordered the ‘Lines of Torres Vedras’ to be built: a long defensive work across the Lisbon peninsular which aided the British in holding back the French.<p>As the campaign season resumed in 1810, the French forces in the peninsular were divided between two Marshalls. Soult held one command and Massena another, but as the two disliked each other they rarely co-operated properly, a situation the British and Portuguese could, and did, exploit. When Massena attacked Portugal with 65,000 men Wellington beat him at Busaco, but was then forced to retreat and refused to advance back out of Torres Vedras; Massena’s army was beaten by a winter while trying to siege the lines; he lost 25,000 men. 1811 saw more back and forth, but the British won another battle, at Fuentes de Onoro, while an allied force under Beresford was mauled. Yet the Spanish armies were crumbling, and French control spreading.</p><p>The French were forced to commit hundreds of thousands of troops, and although this number was reduced as Napoleon gathered an army to <a href="https://www.thoughtco.com/1812-napoleons-invasion-of-russia-1221681" data-type="internalLink" data-component="link" data-source="inlineLink" data-ordinal="5">invade Russia</a>, it represented a heavy drain on imperial resources. France had lost almost fifty per cent of the soldiers who had gone to the Peninsular. They were constantly hamstrung by the nature of the landscape: there were few opportunities to live off the land, as they were able to do in central Europe, while the British could supply their army via their navy. In fact the French really only ever controlled where their army was camped, losing control as soon as they left. The result was more than lost land: Napoleon’s other ventures were starved, his reputation was eroded, and other regions took heart from Iberian success. Meanwhile Britain’s economy was boosted by access to the peninsular, and moral was increased by involvement in the land war.</p><h3>Victory</h3>There were now five French armies in Spain, and three marshals – Soult, Suchet and Marmont – but little agreement between them. In 1812 Wellington’s army was able to take the Spanish fortresses of Ciudad Rodrigo and Badajoz, defeat the French at Salamanca in June – when Marmont had called for help none had been coming, and he lost an arm in a contest of 50,000 French against 60,000 allies - and take Madrid. However an attack on Burgos failed – it was a poorly supplied siege - and Wellington returned to Portugal, avoiding a dithering French army. There were murmurs against Wellington after Burgos, and he was wound up and suffering.<p>In 1813, now leader of all allied troops, he led his forces back into Spain: at the Battle of Vittoria on June 21st 1813 the poorly led French forces under Joseph were heavily defeated and Joseph left Spain. The allied force now fought against a French army which had been unified under Soult, but they ground forward through the Pyrenees and into France, where they beat Soult at Orthez and Toulouse. Napoleon, suffering in the east, gave up on Spain and released Ferdinand VII from prison. He went to Spain and retook the throne. Napoleon had already been forced to abdicate by the time of battle of Toulouse, which occurred too soon for nineteenth century communication to halt it. On St. Helena, Napoleon blamed the ‘Spanish Ulcer’ for his ultimate failure.</p><p>The royals who returned to power rejected the constitution made by the ‘anti-French’ rebels and a wave of score settling against ‘collaborators’ followed.</p><h3>Guerrillas</h3>The struggle between the Spanish and the French is often characterised by the presence of the Spanish guerrillas, irregular forces which caused the regular French troops endless trouble, and which were famed for their brutality and ferocity. By 1812, there were between 25 – 50,000 guerrillas operating.