Avro Manchester & Avro Lancaster - The Avro 679 Manchester was a British twin-engine heavy bomber developed and manufactured by the Avro aircraft company in the United Kingdom. While not being built in great numbers, it was the forerunner of the more famed and more successful four-engined Avro Lancaster, which was one of the most capable strategic bombers of the Second World War. Wiikpedia
Short Stirling Mk III & IV - The Short Stirling was a British four-engined heavy bomber of the Second World War. It has the distinction of being the first four-engined bomber to be introduced into service with the Royal Air Force (RAF) during the war Wikipedia
Vickers Wellington (nicknamed the Wimpy) is a British twin-engined, long-range medium bomber. It was designed during the mid-1930s at Brooklands in Weybridge, Surrey. Led by Vickers-Armstrongs' chief designer Rex Pierson, a key feature of the aircraft is its geodetic airframe fuselage structure, which was principally designed by Barnes Wallis. Development had been started in response to Air MinistrySpecification B.9/32, issued in the middle of 1932, for a bomber for the Royal Air Force. Wikipedia
Armstrong Whitworth A.W.38 Whitley was a British medium/heavy bomber aircraft of the 1930s. It was one of three twin-engined, front line medium bomber types that were in service with the Royal Air Force (RAF) at the outbreak of the Second World War. Alongside the Vickers Wellington and the Handley Page Hampden, the Whitley was developed during the mid-1930s according to Air MinistrySpecification B.3/34, which it was subsequently selected to meet. In 1937, the Whitley formally entered into RAF squadron service; it was the first of the three medium bombers to be introduced.
