After playing a cat and mouse game (see the previous post) from Salamanca to the Douro River and back, Wellington crossed the Tormes River at Salamanca whereas Marmont did it at Alba de Tormes and Huerta, always trying to use the higher speed of the French army to outflank the Allies, cutting their retreat line to Portugal. Wellington was resolved to avoid action other than under the most advantageous of circumstances whereas Marmont was anxious not to engage in full battle but felt constrained to fight some sort of engagement. Both armies occupied the two more prominent features, los Hermanitos o Arapiles. The lesser Arapil was garrisoned by the British whereas the French occupied the Great Arapil.
On 22nd July Marmont thought he had the right opportunity. Dust clouds beyond the hills to the South of Salamanca suggested that Wellington was retreating. British troops could be seen in the hills opposite the French positions, but Marmont assumed this was a rearguard. Marmont resolved to engage these troops while his army marched off to the left and came in behind the British, cutting them off from the rest of Wellington’s army which he took to be retreating in the distant dust cloud
However, although Wellington had sent his heavy baggage on the road to Ciudad Rodrigo, not a rear guard but his whole army still lay concealed in the hills before the French and facing south nor towards the east, as Marmont mistakenly was supposing. At about 2pm Wellington saw the nature of Marmont’s move around his flank. The French divisions were marching along the British and Portuguese front, dangerously strung out and exposing their flanks.
Wellington galloped to his extreme right, where Pakenham’s Third Division was arriving from Salamanca with D’Urban’s Portuguese Cavalry. He ordered an immediate attack on the head of the French column destroying the French avant-garde. The rest of the battle can be followed in several sources, for example at the Wikipedia
The Allied losses were around 5,000 men whereas the French lose 6,000 dead or wounded and 7,000 captured. The battle established Wellington as an offensive general. The French general Foy wrote in his diary that Wellington "defeated an army of 40,000 men in 40 minutes".
After this battle, the French retreated towards Burgos, whereas Wellington entered in Madrid, but this is another history.
More information about the battle in web site of the Los Arapiles historical site.
The issue 15 of Alkaid is also devoted to the battle of Salamanca and the Campaign of 1812 of the Peninsular War.
The above scheme corresponds to a Napoleon’s Battles Scenario . You can download it (and read the AAR) at the main web site: Salamanca 1812