The 22nd July 1812 was one of the greatest days in the British Army’s history, as the Duke of Wellington's Anglo-Portuguese army won a resounding victory over the French. The result at Salamanca enabled Wellington to march into Madrid within three weeks, yet by the end of the year, Wellington had been forced back to the Portuguese border in the same position that he was in before the start of the Salamanca campaign. This setback appears to suggest that the potential of Salamanca had been wasted.
Criticism of Wellington's exploitation of Salamanca extends to the battle itself, and the consolidation of his victory. These criticisms are not fair, however, as the situation was complex. It is true that Wellington sent troops in the wrong direction as he pursued the French. His aim was to cut them off from a vital ford at Huerta, as he believed that his Spanish allies occupied a castle overlooking the only other escape route (a bridge at Alba de Tormes). However, the Spanish had evacuated the castle earlier that day, as they were concerned by the size of the French force in the area, and had no inkling that Wellington was about to secure a famous victory. The Spanish therefore cannot be blamed for taking what was basically a sensible course of action, although this may explain Wellington's actions. Wellington certainly heaped blame on the Spanish for their actions, although the historian David Gates suggests that this was an excuse, whilst Rory Muir has questioned whether holding the castle would really have made any difference. Either way, as Wellington himself acknowledged this was a: 'little misfortune which does not diminish the honour acquired by the troops in the action'. The facts speak for themselves: a French army had been comprehensively defeated, leaving 11,790 men killed or taken prisoner.
It has to be said, that in the weeks after Salamanca, Wellington's usual dynamic style appeared to desert him. His position in the centre of Spain, with long and vulnerable supply lines to Lisbon, left him vulnerable. Around him were three French armies – the one which he had just defeated to the north, a small army guarding Madrid under Joseph Bonaparte (the French imposed King of Spain), and a large force to the south in Andalucia under Marshal Soult. If he attacked either of the first two, Soult’s army could march north and cut Wellington’s supply lines, leaving him stranded in central Spain. If he marched south to deal with that army, then the French troops in the north could do the same thing. Wellington marched on Madrid, forcing Joseph to evacuate the Spanish capital without a fight, which was a huge propaganda victory. Even though the British were forced to evacuate the city themselves when they retreated at the end of the year, the French only re-occupied it for 9 days. Madrid had been liberated, showing the French hold on Spain had been shaken to the core.
Ultimately, whilst the Allied army may have ended 1812 back at the Portuguese border, Salamanca fundamentally transformed the strategic situation in the Iberian Peninsula. In the aftermath of the battle, other French armies in Spain had to send reinforcements to the army that Wellington had defeated, thereby weakening their own positions. Furthermore, in Andalucia, Soult was force to abandon his lengthy siege of Cadiz, the home of Spanish government. He brought his 60,000 men to join the 'Army of Portugal' (the French Army which Wellington defeated at Salamanca), with the result that Wellington now faced nearly 120,000 men (far outnumbering his force of 73,000). Retreat was therefore the only sensible option, whilst Soult’s actions in effect meant that Wellington had succeeded in liberating southern Spain without firing a single shot at the troops stationed there. With French troops in a much more concentrated position in northern and central Spain, the path had been cleared for the even more decisive campaign of 1813.
Salamanca proved, yet again, that the French were not invincible. Wellington's bold attack showed that the British Army could do much more than win defensive battles. Whilst Napoleon may have dismissed the result as irrelevant when news reached him on the eve of Borodino, Salamanca laid the foundations for the end of the Peninsular War, and the invasion of France. A wasted victory? Definitely not!
For more information about the Battle of Salamanca and its aftermath, visit the relevant pages of this website: Peninsular War > Campaign of 1812.