The Battle of Barrosa (Chiclana, 5 March 1811) was part of an unsuccessful manoeuvre to break the siege of Cádiz in Spain during the Peninsular War. During the battle, a single British division defeated two French divisions and captured a regimental eagle.Cádiz had been invested by the French in early 1810, leaving it accessible from the sea, but in March of the following year a reduction in the besieging army gave its garrison of Anglo-Spanish troops an opportunity to lift the siege.