German bombers in formation, April 1941.

German bombers in formation, April 1941.

Operation Retribution (German: Unternehmen Strafgericht) also known as Operation Punishment, was the codename used for the April 1941 German bombing of Belgrade, the capital of the Kingdom of Yugoslavia, in the first days of the German-led Axis invasion of Yugoslavia. The operation commenced on 6 April and concluded on 7 or 8 April, resulting in the paralysis of Yugoslav civilian and military command and control, widespread destruction largely in the centre of the city, and significant civilian casualties. The bombing of Belgrade was preceded by the commencement of the ground invasion a few hours earlier, and also coincided with air attacks on a large number of Royal Yugoslav Air Force airfields and other strategic targets across Yugoslavia. The invasion resulted in the surrender of Yugoslav forces on 17 April.