The Battle of Arlabán, also known as the First Surprise of Arlabán, took place at the heights of Arlabán, the mountain pass that separates the Basque provinces of Guipúzcoa and Álava, on 25 May 1811, during the Peninsular War. Aided by local guerrilla groups that knew the terrain well, Espoz y Mina had positioned his guerrilleros on both sides of the pass, on the route to France, some 20 km north of Vitoria, at four o'clock in the morning.