The Spanish Peninsular War (1808-1814) was a conflict during the Napoleonic Wars in which Spain, supported by the United Kingdom and Portugal, fought against the French Empire. The war began when Napoleon Bonaparte invaded Spain, leading to widespread resistance from Spanish citizens and guerrilla fighters. The conflict resulted in significant political and social changes in Spain, including the establishment of the Cortes of Cádiz, which created the Spanish Constitution of 1812. Ultimately, the war ended with the defeat of French forces, leading to the restoration of the Spanish monarchy and a shift in power dynamics in Europe.