Circus was the codename given to operations by the Royal Air Force (RAF) during the Second World War where bombers, with a mass escort of fighters, were sent over continental Europe to bring Luftwaffe 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 Luftwaffe.
At first medium bombers such as the Handley Page Hampden were used but even with many escorts they were too vulnerable to flak and German fighters. The Hampdens were replaced with Bristol Blenheim light bombers but those fared no better. Heavy bombers such as the Short Stirling were easier to escort but after several missions Bomber Command needed them back.
The "Hurribomber", a fighter-bomber development of the Hawker Hurricane, was used with better results, although the small bomb load carried by this aircraft caused little damage.
There were other codenames for similar missions.
- Ramrod: similar to Circus but with destroying a target being the principal aim. An example would be Operation Ramrod 16.
- Ranger: large fighter formation intrusion over occupied territory with aim of wearing down German fighter force.
- Rhubarb: small-scale freelance fighter sorties against ground targets of opportunity.
- Roadstead: low-level attack on coastal shipping.