The airline operated its first service from London Luton to Glasgow in 1995 and began flights to Belfast International at Aldergrove shortly afterwards. It now operates a huge network of flights to UK and European destinations from BIA.
The airline's decision to operate flights from George Best Belfast City to Luton was taken last year and there has been speculation about more easyJet services being provided from this airport which lost its Ryanair network at the end of last month.
Flybe which is Belfast City's largest operator has taken over the Bristol, East Midlands and Liverpool routes vacated by Ryanair.
Two additional aircraft have been based at the airport to operate these flights.
Manx2 has also made Belfast City its first pernanent base outside the Isle of Man. It is reporting good load factors on its service to Cork which it introduced when Aer Arran pulled off the route.
Manx2's 19 seater 'Metroliner' flies between the two cities twice a day. The airline also now uses Belfast City for all its Isle of Man flights to and from Northern Ireland as well as its services to Galway and Blackpool.