What combined forces prevented France from controlling the Iberian Peninsula in 1814?

The combined British, Portuguese, and Spanish forces played a crucial role in thwarting French ambitions in the Iberian Peninsula during the Napoleonic Wars. By forming a coalition, these forces effectively coordinated their military efforts, which significantly undermined French control.

British forces, under the leadership of figures such as the Duke of Wellington, provided experienced military strategies and resources. At the same time, the Portuguese, supported by the British, were integral in resisting French occupation. The Spanish contributed not only by fighting on multiple fronts but also through guerrilla warfare tactics, which further drained French resources and morale.

This alliance reflected a broader resistance to Napoleonic expansionism and exploited the vulnerabilities of the French military. By the end of 1814, the relentless efforts of these combined forces had resulted in a substantial decline in French power on the Iberian Peninsula, ultimately leading to the expulsion of French troops and the restoration of local authorities.