The Spanish Peninsular War or Spanish War of Independence was fought between the French under Napoleon and an alliance of Spanish, Portuguese and British forces. In 1807 France and Spain had been allies in an invasion of Portugal, where Spain anticipated that a victory would enable it to gain Portuguese territories. However, in 1808 Napoleon turned on his Spanish allies and forced Ferdinand VII to abdicate in favour of Napoleon’s brother, Joseph. But on May 2, 1808 there was an uprising in occupied Madrid which was brutally suppressed followed by a regime of repression. This sparked off revolts across Spain and Portugal.
There were reprisals and massacres in cities such as Tarragona, where 15,000 civilians were massacred, Cordoba, Saragossa and numerous towns and villages. After Spanish troops were routed by the French some joined irregular forces and the conflict became a guerrilla war with atrocities being committed by both sides. French troops would take reprisals on local towns and villages when attacked by guerrillas and the guerrillas would then commit atrocities on isolated French troops and collaborators. As the conflict continued both sides began to mutilate their prisoners as well as kill them. This was vividly captured by Goya in his series of etchings, The Disasters of War.
British forces in Spain were also guilty of atrocities. When they captured San Sebastian in 1812 half the population was killed and there were massacres following the British capture of Ciudad Rodrigo and Badajoz.
The extreme violence of the Peninsular War was partly due to the fact that it was so difficult to distinguish between irregular guerrillas and non-combatant civilians. The issue of how regular troops should respond to attacks from guerrillas who then disappeared or were sheltered by local people became increasingly significant in the 19th and 20th centuries and still presents problems in contemporary conflicts.