Qantas Airways Limited is the flag carrier of Australia and its largest airline by fleet size, international flights and international destinations. It is the world's third-oldest airline still in operation, having been founded in November 1920; it began international passenger flights in May 1935. Qantas is an acronym of the airline's original name, Queensland and Northern Territory Aerial Services, as it originally served Queensland and the Northern Territory, and is popularly nicknamed "The Flying Kangaroo". Qantas is a founding member of the Oneworld airline alliance.