The first design concepts were made in 1947. The Javelin had an unusual design with delta wings and a delta-shaped T-tail, making its first flight in 1951,. In 1954 the first of 40 Javelin FAW.Mk.1 was finished. In the year 1955 the first flight of the FAW.Mk.2 was made, 25 of it were built. In 1956, 21 T. Mk. 3 trainer aircraft were built. Because of continuing technical problems, service entry of the Javelin was delayed to 1956. Many more upgraded derivatives were built like the FAW.Mk.4, Mk.5 and Mk.6. But only the last two derivatives, Mk.7 and Mk.8, showed significant upgrades, like afterburning engines. Production ended after 381 built aircraft with the Mk. 8; upgraded Mk.7 were called Mk.9. The Javelin was also used at the end of the 1950s/at the beginning of the 1960s by the RAF Germany as an all-weather interceptor. The Javelin went out of service in 1968. Today 10 aircraft are based in museums.