Operation SUSSEX

Operation SUSSEX was a tripartite joint secret intelligence operation of the American Secret Intelligence Branch (SI) at OSS/London, the British Secret Intelligence Service (SIS or MI6), and the French Bureau Central de Renseignements et d'Action (BCRA). The plan under which this operation was carried out was Operational Plan SUSSEX, or simply the SUSSEX Plan (French: Plan SUSSEX). During SUSSEX, the BCRA recruited exclusively French soldiers from within the Free French Army who were trained in espionage tactics in the UK and then dropped by parachute into Occupied France in two-person teams to report on the locations of strategic and tactical military targets and objectives in the lead-up to D Day, and especially the Normandy Landings. These teams, collectively known as the SUSSEX Network, were deployed to areas not already covered by the existing espionage capabilities of the French Resistance.

The SUSSEX teams were divided into BRISSEX teams and OSSEX teams. BRISSEX teams were managed, trained, and deployed by the British SIS into the British-Canadian 21st Army Group objective areas north of the Seine. OSSEX teams, managed, trained, and deployed by the American OSS, were those dropped into American objective areas south of the Seine. One agent in each team was trained as an observer. The other agent in each team was specially trained as a radio operator, and those teams on the ground then communicated by secret radio and S-Phone to radio stations in Great Britain; the OSSEX teams with Station Victor, and the BRISSEX teams with another station. Communication with the continent, however, was carefully controlled to ensure that French radio frequency bands did not become "overcrowded."

In total, 120 SUSSEX agents were parachuted into Occupied France as a part of Operation SUSSEX. BRISSEX teams were dropped by the Royal Air Force, and OSSEX teams were dropped by the Carpetbaggers. On D Day, there were already 7 BRISSEX and 7 OSSEX teams deployed behind enemy lines reporting on enemy movements. Overall, between February and September 1944, 2 Pathfinder teams and 52 SUSSEX teams were parachuted into Axis-occupied territories.