The Bristol Blenheim is a British light bomber used extensively during the first two years of WW2. The Blenheim, named after the famous battle, was a twin-engine, three seated high-performance light-bomber powered by two Bristol Mercury VIII engines driving a three-bladed controllable pitch propeller. It first flew in 1935 and was introduced into RAF service in March 1937 with 114 Squadron.

The original Blenheim’s were lightly armoured with only a single Vickers machine gun in a dorsal turret. By the outbreak of WW2 the Blenheim, along with the Handley Page Hampden, Armstrong Whitworth Whitley, Fairey Battle and Vickers Wellington formed the backbone of British Bomber Command. However, it became clear very early on in the opening months of the war that the Blenheim was totally outclassed by the German opposition and deemed obsolete. Some additions were made significantly with a gun pod mounted externally under the ventral fuselage comprising four Browning .303 Machine guns. Improvements were made in early 1941 with the Mk.IV but it was too little too late. However, the type remained in service, despite heavy losses, until it was replaced in 1942 with the introduction of the American Boston medium bomber. Most Blenheims were quickly retired from service.

There is one surviving original Blenheim in Finland, a Mk.IV BL-200 of the Finnish Air Force and is displayed at the Aviation Museum in Tikkakoski.

All other Blenheims on display have been rebuilt from Bristol Bolingbroke Mk.IV aircraft including the airworthy replica which forms part of the BBMF and is based at Coningsby with the serial L6739, as a Blenheim Mk.I.