Millennium Offensive

The German city of Cologne was bombed in 262 separate air raids by the Allies during World War II, all by the Royal Air Force (RAF) but for a single failed post-capture test of a guided missile by the United States Army Air Forces. A total of 34,711 long tons of bombs were dropped on the city by the RAF.

While air raid alarms had gone off in the winter/spring of 1940 as British bombers passed overhead, the first bombing took place on 12 May 1940. The most notable attack on Cologne was the first 1,000 bomber raid on 30/31 May 1942.

The first ever 1,000 bomber raid by the RAF was conducted on Cologne on the night of 30/31 May 1942. Codenamed Operation Millennium, the massive raid was launched for two primary reasons:

At this stage of the war Bomber Command only had a regular front line strength of around 400 aircraft, and were in the process of transitioning from the twin engined medium bombers of the pre-war years to the newer more effective four-engined heavy bombers such as the Handley Page Halifax and Avro Lancaster. By using bombers and men from Operational Training Units (OTUs), 250 from RAF Coastal Command and from Flying Training Command, Harris could easily make up the 1,000 aircraft. However, just before the raid took place, the Royal Navy refused to allow the Coastal Command aircraft to take part in the raid. The Admiralty perceived the propaganda justifications too weak an argument against the real and pressing threat of the U-boats in the Battle of the Atlantic. Harris scrambled around and, by crewing 49 more aircraft with pupil pilots and instructors, 1,047 bombers eventually took part in the raid, two and a half times more than any previous raid by the RAF. In addition to the bombers attacking Cologne, 113 other aircraft on "Intruder" raids harassed German night-fighter airfields.

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