The codename Circus was given to operations of British Royal Air Force (RAF) during World War II where bombers, heavily escorted by fighters, were sent over continental Europe to bring enemy fighters into combat. These were usually formations of 20 to 30 bombers escorted by up to 16 squadrons of escort fighters. Bomber formations of this size could not be ignored by the German Luftwaffe.
At first medium bombers such as the Handley Page Hampden were used but even with heavy escort they were too vulnerable to flak and German fighters. They were replaced with Bristol Blenheim bombers but they fared no better. Heavy bombers such as the Short Stirling were a better fit, but after several missions bomber command needed them back.
There were other codenames for similar missions.
- Ramrod – similar to Circus, but with intention of destroying a target. An example would be Operation Ramrod 16
- Ranger – large-formation intrusion over enemy territory with aim of wearing down enemy fighter force.
- Roadstead – low-level attack on coastal shipping.
- Rhubarb – small-scale freelance fighter sorties against ground targets of opportunity.
- Caygill, Peter. The Biggin Hill Wing – 1941: From Defence to Attack. Pen & Sword Aviation, 2008. ISBN 978-1844157464
- 1941: The Difficult Year – Dispatch submitted to the Secretary of State for Air on 29 February 1948, by Marshal of the Royal Air Force Sir Sholto Douglas, G.C.B., M.C., D.F.C