A professional tennis player is said to have won the Grand Slam when he or she has won all four of the sport’s top professional tournaments in one calendar year. Very few singles players have achieved this feat.

The top four tournaments, known as Grand Slam tournaments, are the Australian Open (run in January), the French Open (or Roland Garros, run in May and June), Wimbledon (run in June and July), and the U.S. Open (run in August and September). Each of these top-tier tournaments takes place during a two-week span and routinely features the top players in the world.

Wimbledon began in 1877. The U.S. Open began in 1881. Ten years later, the French Open began. Last in the chronological listings is the Australian Open, which began in 1905. Wimbledon was the only tournament designated as a “major” tournament, until 1924, when the idea of the Grand Slam was born.

American Don Budge in 1938 was the first singles player to win the Grand Slam. Budge was known for his height (he was 6’ 2” tall) and his backhand. He won Wimbledon and the U.S. Open in 1937 and then repeated as champion the following year, also winning at the Australian and French Opens. In all, he won 14 Grand Slam tournaments. He enlisted in the Army Air Force in 1942, and a wartime injury prevented his comeback on the tennis court.

American Maureen Connolly won the Grand Slam in 1953. Connolly first won the U.S. Open in 1951, when she was 16. She repeated that feat the following year and added a Wimbledon title to her list of successes. In 1953, Connolly, nicknamed “Little Mo,” made her only trip to Melbourne, to play in the Australian Open. She won that tournament, won in Paris, and then repeated as champion at Wimbledon and the U.S. Open, in doing so clinching her Grand Slam. Connolly won every Grand Slam tournament she entered, 9 in all, amassing a record of 50-0. A horse riding accident cut short her career.

Rod Laver of Australia is the only player to have twice won all four Grand Slam tournaments in the same year. He won his first Grand Slam title in 1960, in his native country. He won Wimbledon the following year. He stepped up his game in 1962, claiming wins in all
four Grand Slam tournaments and also led his country’s team to victory in the Davis Cup. Seven years later, Laver again won the Grand Slam. He won 11 Grand Slam singles titles in all and had tremendous success in doubles and mixed doubles as well, winning six Grand Slam doubles titles and two Grand Slam mixed doubles titles. Laver led Australia to three other Davis Cup wins.

Margaret Smith Court was a dominating force in women’s tennis for many years. She won her first Grand Slam title in her native country of Australia in 1960, when she was 18. She won the Australian Open 11 times in all, including six straight. She won the U.S. Open seven times, the French Open five times, and Wimbledon three times. In all, she won 24 Grand Slam titles in singles. In 1970, she won the Grand Slam. In that year, she entered 27 tournaments and won 21 of them, ending the year with an overall singles record of 104-6. She also won the Grand Slam in mixed doubles twice, once with the same partner (countryman Kenneth Fletcher, in 1963) and once with three different players (, in 1965).

Germany’s Steffi Graf won 22 Grand Slam single’s titles in her career, beginning with the French Open in 1987. The following year, when she was 19, Graf won all four Grand Slam titles and also won the Gold Medal at the Summer Olympics Games, in Seoul. She won Wimbledon seven times in all, the French Open six times, the U.S. Open five times, and the Australian Open four times. She retired in 1999. Graf played doubles a bit in her career. She reached several Grand Slam finals, including winning Wimbledon in 1988, her Grand Slam year, partnering with Argentina's Gabriela Sabatini.