In the closing stages of the Second World War, the aircraft manufacturer de Havilland began development of a new small twin-engined passenger aircraft, the DH 104 Dove, intended as a replacement for the earlier Dragon Rapide and which soon proved to be successful. As a further development, the company basically enlarged the Dove; the fuselage was lengthened to make room for more passengers or freight, and the wingspan was increased to make room for two more engines. The Heron was of all-metal construction, and was laid out as a conventional design; the resulting aircraft could use many of the parts originally designed for the Dove, thus simplifying logistics for airlines using both types.