No. 100 (Bomber Support) Group was a special duties group within RAF Bomber Command. The group was formed on 11 November 1943 to consolidate the increasingly complex business of electronic warfare and countermeasures in one organisation. The group was responsible for the development, operational trial and use of electronic warfare and countermeasures equipment. It was based at RAF stations in East Anglia, chiefly Norfolk. Top Mosquito ace with 100 Group was Wing Commander Branse Burbridge of 85 Squadron, with 21 claims from 1944–45.