Deutsche Lufthansa AG, commonly known as Lufthansa, is the largest German airline and, when combined with its subsidiaries, also the largest airline in Europe both in terms of fleet size and passengers carried during 2017. The name of the company is derived from the German word, Luft 'air' and Hansa, the Hanseatic League. Lufthansa is one of the five founding members of Star Alliance, the world's largest airline alliance, formed in 1997.