The four Grand Slams represent the pinnacle of the tennis calendar each year as the world's best players aim to cement their place in the history of the sport.
With the Australian Open, French Open, Wimbledon and US Open taking place between January and September, the winners and finalists of these tournaments naturally tend to show which players are dominating at the very highest level.
We take a look at which tennis players have reached the most Grand Slam singles finals in history.
Novak Djokovic - 37
Roger Federer - 31
Rafael Nadal - 30
Ivan Lendl - 19
Pete Sampras - 18
Rod Laver - 17
Bjorn Borg & Ken Rosewall - 16
Roy Emerson, Bill Tilden, Andre Agassi & Jimmy Connors - 15
Chris Evert - 34
Serena Williams - 33
Martina Navratilova - 32
Steffi Graf - 31
Margaret Court - 29
Helen Wills - 22
Billie Jean King, Evonne Goolagong Cawley & Doris Hart - 18
Venus Williams & Helen Jacobs - 16