How did the Duke of Wellington help defeat French forces in Spain?

Arthur Wellesley, 1st Duke of Wellington, played a pivotal role in defeating French forces in the Peninsular War through a combination of defensive strategy, logistical persistence, and decisive offensive maneuvers.

Key aspects of his campaign included:

• Defensive Fortification: Wellington utilized a scorched-earth policy and constructed the formidable lines of Torres Vedras in Portugal. These defenses successfully halted French advances and protected his base of operations, forcing the French to eventually evacuate Portugal in 1811.12
• Strategic Offensives: Operating from his secure Portuguese base, Wellington launched gradual advances into Spain. He secured critical victories at Talavera (1809), Salamanca (1812), and the decisive Battle of Vitoria (1813).12
• Exhausting French Resources: By maintaining a persistent presence, Wellington forced the French to commit vast resources to the peninsula. This pressure, combined with the activities of local guerrilla warfare fighters, significantly wore down French strength, especially as Napoleon diverted troops to his Russian campaign.2

Following the victory at Vitoria, Wellington drove the French forces across the Pyrenees and into France, effectively ending French control in Spain by 1814.13