The Manchester Open previously known as the Northern Lawn Tennis Championships, the Northern Championships, the Northern Tennis Tournament and the Manchester Trophy was a grass court tennis tournament on the ATP Tour held at the Northern Lawn Tennis Club, in the Didsbury suburb of Manchester, Great Britain. The tournament had been held annually from 1880 to 2009. Prior to the creation of the International Lawn Tennis Federation and the establishment of its world championship events in 1913 it was considered by players and historians one of the four most important tennis tournaments to win. the others being Wimbledon, the U.S. National championships and the Irish Championships. Between 1970 and 1989 it was part of the men's Grand Prix tennis tour.