On the evening of July 27th 1809 20,000 British troops and their Portuguese allies, commanded by General Wellesley (later to become the Duke of Wellington), together with a Spanish army took on 46,000 French troops under Marshal Victor. Following several unsuccessful assaults on the British lines, the French eventually gave up and withdrew with the loss of 7,390 killed or wounded. The British lost 5,500, many burnt to death when the dry grass of the battlefield caught fire (interestingly this was a deliberate battle tactic carried out by the Wehrmacht during their approach to Stalingrad in 1942). Not only had the Spanish refused to fight on a Sunday, they also reneged on their promise to provide food and supplies and even abandoned the British wounded to the French: the Spanish were never trusted after that and Wellington was forced to withdraw back to Portugal.
The 48th Foot - later the Northamptonshire Regiment and now incorporated into the Royal Anglian Regiment - were the stars of the battle making a bayonet charge against a French infantry division driving them from the field. For their heroic action the 48th Foot were subsequently awarded battle honours.