Napoleon recalled to France numerous soldiers to reconstruct his main army after his disastrous invasion of Russia. By 20 May 1813 Wellington marched 121,000 troops (53,749 British, 39,608 Spanish and 27,569 Portuguese) from northern Portugal across the mountains of northern Spain and the Esla River to outflank Marshal Jourdan's army of 68,000, strung out between the Douro and the Tagus. The French retreated to Burgos, with Wellington's forces marching hard to cut them off from the road to France. Wellington himself commanded the small central force in a strategic feint, while Sir Thomas Graham conducted the bulk of the army around the French right flank over landscape considered impassable.

Wellington launched his attack with 57,000 British, 16,000 Portuguese and 8,000 Spanish at Vitoria on 21 June, from four directions.

At the Battle of Vitoria (21 June 1813) a British, Portuguese and Spanish army under the Marquess of Wellington broke the French army under King Joseph Bonaparte and Marshal Jean-Baptiste Jourdan near Vitoria in Spain, eventually leading to victory in the Peninsular War.