The action was the first major incident in the British army's harrowing retreat to the coast and ultimate evacuation by sea.

Sir John Moore led a British army into the heart of northwestern Spain with the aim of aiding the Spanish in their struggle against the French occupation.

However, Napoleon had entered Spain at the head of a large army in order to retrieve French fortunes.

The bridge at Castrogonzalo had been demolished by British engineers early on the 29th, and it was not until about 9:00 in the morning that Charles Lefebvre-Desnouettes, a noted favourite of Napoleon, was able to ford the river with three strong squadrons of his chasseurs and a small detachment of Mamelukes.

In an area where their flanks were covered by walls the British, now reinforced by a troop or squadron of the 3rd Hussars KGL and commanded by Brigadier-General Stewart, counter-attacked and a confused melee ensued.

[5] The French had gained the upper hand in the fight and were preparing to deliver a final charge when Lord Paget made a decisive intervention.

Napoleon had viewed the action from a height overlooking the river;[5] his reactions were rather muted and he made light of the losses to, and humbling of, his "Cherished Children."

[13] The French general was imprisoned in England where he eventually broke his parole, an unpardonable sin according to English public opinion, and escaped back to France, whereupon Napoleon reinstated him to his former command of the guard chasseurs.