Designed to meet a US Army Air Corps specification for an attack bomber, the Martin XA-22 prototype was a twin-engine cantilever low/mid-wing monoplane with retractable tailwheel landing gear and accommodation for a crew of three. It was flown for the first time on 14 March 1939, but following official tests was rejected by the USAAC. However, the company had received a first production order for 115 aircraft from France even before the prototype had flown, but the start of delivery was delayed until the US arms embargo was lifted in October 1939; by that time France had contracted for an additional 100 aircraft. Only 140 of these Model 167F aircraft were delivered before the French armistice in June 1940, having the French designation Martin 167A-3 and seeing action against Axis forces until June 1940 and subsequently, with Vichy forces in West Africa and the Middle East, against the Allies.
With the collapse of French resistance in Europe, the outstanding 75 aircraft on order were diverted to the UK for service with the RAF and these, together with an additional 75 ordered by the RAF,
were designated as Maryland Mk 1.
All were powered by 783kW R-1830-SC3G Twin Wasp radial engines with single-stage superchargers. Further British orders followed for an improved Maryland Mk II with more powerful engines and two-stage superchargers, a total of 150 of this version being delivered to the RAF. Marylands were deployed initially for target towing and long-range reconnaissance, proving to be particularly valuable in this latter role, and were also used as light bombers. The first operational unit to receive the Maryland, in September 1940, was No. 431 Flight (later No. 69 Squadron) formed at Malta, and the type saw service in the Western Desert with Nos 39 and 223 Squadrons. Some 72 of the RAF's Marylands were re-allocated to serve with Nos 12, 20, 21 and 24 Squadrons of the South African Air Force. Marylands also saw service with the Fleet Air Arm. Among the notable operations of the type were the reconnaissance sorties that preceded the successful Fleet Air Arm attack in November 1940 on the Italian fleet in harbour at Taranto. Another FAA Maryland
reported that the Bismarck and Prinz Eugen were at sea in May 1941.
