British Airways (BA) is the flag carrier airline of the United Kingdom and its largest airline based on fleet size, international flights and international destinations. When measured by passengers carried it is second-largest in Britain, behind easyJet. The airline is based in Waterside near its main hub at London Heathrow Airport.
British Airways is a founding member of the Oneworld airline alliance, along with American Airlines, Cathay Pacific, Qantas, and the now defunct Canadian Airlines. The alliance has since grown to become the third-largest, after SkyTeam and Star Alliance. British Airways merged with Iberia on 21 January 2011, formally creating the International Airlines Group (IAG), the world's third-largest airline group in terms of annual revenue and the second-largest in Europe.