Heathrow Airport (IATA: LHR, ICAO: EGLL) is a major international airport 23 km west of central London, United Kingdom. Along with Gatwick, Stansted, Luton, Southend and London City, Heathrow is one of six airports with scheduled services serving the London area and the second busiest airport in the world by international passenger traffic, as well as the busiest airport in Europe by passenger traffic. Heathrow Airport originated in 1929 as a small airfield but the development of the whole Heathrow area as a very much larger airport began in 1944: it was stated to be for long-distance military aircraft. World War II had ended, the government continued to develop the airport as a civil airport; it opened as London Airport in 1946 and was renamed Heathrow Airport in 1966. The airport is the primary hub for British Airways and the primary operating base for Virgin Atlantic.