"The Martin 187 Baltimore was a two-engined light attack bomber built by the Glenn L. Martin Company in the United States, originally ordered by the French in May 1940 as a follow-up to the earlier Martin Maryland, then in service in France. With the fall of France, the production series was diverted to Great Britain. Baltimore development was hindered by a series of problems, although the type eventually became a highly versatile combat aircraft. Produced in large numbers, the Baltimore was not used in combat by the United States forces, but eventually served with the British, Canadian, Australian, South African, Hellenic and the Italian air forces.
Initially designated the A-23 (derived from the A-22 Martin 167 Maryland design), the Model 187 (company designation) had a deeper fuselage and more powerful engines. The Model 187 met the needs for a light to medium bomber, originally ordered by the Anglo-French Purchasing Commission as a joint project in May 1940. The French Air Force sought to replace the earlier Maryland; 400 aircraft being ordered. With the fall of France, the Royal Air Force (RAF) took over the order and gave it the service name Baltimore. To enable the aircraft to be supplied to the British under the Lend-Lease Act the United States Army Air Forces designation A-30 was allocated.
With the passing of the Lend Lease Act two further batches of 575 and then 600 were provided to the RAF"