Mittelwerk was a German World War II factory built underground in the Kohnstein to avoid Allied bombing. It used slave labor from the Mittelbau-Dora concentration camp to produce V-2 ballistic missiles, V-1 flying bombs, and other weapons.

Operation Hydra was an attack by RAF Bomber Command on a German scientific research centre at Peenemünde on the night of 17/18 August 1943. Group Captain John Searby, commanding officer of No. 83 Squadron RAF, commanded the operation, the first time that Bomber Command used a master bomber to direct the attack of the main force. Hydra was the first operation against the German V-weapon programme, a campaign later known as "Crossbow". The British lost 40 bombers and 215 aircrew, and several hundred enslaved workers in the nearby Trassenheide forced labour camp were killed. The Luftwaffe lost twelve night-fighters and about 170 German civilian personnel were killed, including two V-2 rocket scientists. Assessments of the raids effectiveness vary; the United States Strategic Bombing Survey (1945) called the raid "not effective", while in 1943, Joseph Goebbels wrote of a delay in the programme of six to eight weeks.