This paper describes the design and development of the HS. 748 short/medium range turboprop aircraft. At the RAeS Convention on “Economical Factors in Aviation” held on the 13th/14th May 1970, Mr. Knight of BAC stated, when analysing post-war British civil aircraft projects, that “there are really only three types that can be called true commercial aircraft successes. They are the Vickers Viscount, the HS.748 and the BAC One-Eleven”. This paper discusses the philosophy behind the original design of the aircraft, its development to date, its in-service history and also gives examples of the many different projects based on the HS.748 which have been and which are still being considered. The aircraft is described as the HS.748 throughout this lecture as this is its current designation. It should not be forgotten, however, that this aircraft was designed and flown as the Avro 748 for at least three years.