British and Spanish forces were en route to Cadiz to help lift a French siege when they were attacked at Barrosa. British soldiers did most of the fighting and won the battle, although they lost a quarter of their men. Angry at the Spanish lack of assistance in the battle, Lieutenant-General Thomas Graham (1748–1843) withdrew his army. At the same time the French general, Masséna, ordered a retreat from Portugal. During the invasion, he had lost 25,000 men and the campaign is believed to have failed as his force was simply too small to match Wellington’s. On his route out he left a garrison at Aleida which Wellington promptly blockaded. Masséna returned to try and relieve the fortress but was defeated at Fuentes d’Onoro and fell back, escaping through allied lines much to Wellington’s disgust. At the same time, Sir William Beresford was ordered to relieve the city of Badajoz from the French. His siege did not do well against a determined French defence and he was eventually attacked at Albuera by General Soult. The battle was won by Beresford and his Spanish and Portuguese allies but both sides suffered enormous losses: the French lost a quarter of their force (6,000) and the British lost two fifths (4,000). The French remained in command of Badajoz until the following year when Wellington personally invested the city on 17 March, taking it on the 7 April. Wellington took heavy losses and although it was a Spanish town, the sack of Badajoz was excessive in its drunken violence.

See Rory Muir, Britain and the Defeat of Napoleon, 1807-1815 (New Haven and London: Yale University Press, 1996), pp. 149-52, 200-201.