52 B-26As were delivered to the Royal Air Force under the name Marauder I. Their RAF serials were FK109 to FK160. The first three Marauder Is for the RAF were ferried across the Atlantic late in 1941. Most of them went to the Middle East in 1942 for service in Egypt in an attempt to defend the Suez Canal against the advance of Field Marshal Erwin Rommel's Afrika Korps.
The first RAF squadron to receive the Marauder I was No 14, the aircraft replacing the unit's Blenheims in August of 1942. Conversion training was completed without any difficulty. The RAF was actually the first service to introduce the Marauder into action in the Mediterranean, the first operational mission by RAF Marauders being flown on October 28, 1942 This was a reconnaissance sortie flown as part of the El Alamein battle. Subsequently, anti-shipping sweeps were flown and bombs were dropped on enemy installations in Tunisia. Mines were sewn in the harbor at Tunis. Unfortunately, one Marauder was shot down by mistake by RAF Spitfires on December 28, 1942.