Deutsche Lufthansa AG, commonly known as Lufthansa, is the largest German airline and, when combined with its subsidiaries, also the largest airline in Europe, in terms of fleet size, and the second largest airline in terms of passengers carried during 2016. It operates services to 18 domestic destinations and 197 international destinations in 78 countries across Africa, the Americas, Asia, and Europe, using a fleet of more than 270 aircraft. Lufthansa is one of the five founding members of Star Alliance, the world's largest airline alliance, formed in 1997.