The Battle of Barrosa was an unsuccessful French attack on a larger Anglo-Portuguese-Spanish force attempting to lift the siege of Cádiz

Cádiz

Cadiz is a city and port in southwestern Spain. It is the capital of the homonymous province, one of eight which make up the autonomous community of Andalusia....

, Spain

Spain

Spain , officially the Kingdom of Spain languages]] under the European Charter for Regional or Minority Languages. In each of these, Spain's official name is as follows:;;;;;;), is a country and member state of the European Union located in southwestern Europe on the Iberian Peninsula...

 during the Peninsular War

Peninsular War

The Peninsular War was a war between France and the allied powers of Spain, the United Kingdom, and Portugal for control of the Iberian Peninsula during the Napoleonic Wars. The war began when French and Spanish armies crossed Spain and invaded Portugal in 1807. Then, in 1808, France turned on its...

. During the battle, a single British division

Division (military)

A division is a large military unit or formation usually consisting of between 10,000 and 20,000 soldiers. In most armies, a division is composed of several regiments or brigades, and in turn several divisions typically make up a corps...

 defeated two French divisions and captured a regimental eagle

French Imperial Eagle

French Imperial Eagle refers to the figure of an eagle on a staff carried into battle as a standard by the Grande Armée of Napoleon I during the Napoleonic Wars....

.

Cádiz had been invested

Investment (military)

Investment is the military tactic of surrounding an enemy fort with armed forces to prevent entry or escape.A circumvallation is a line of fortifications, built by the attackers around the besieged fortification facing towards the enemy fort...

 by the French in early 1810, 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.