Court is one of only three players in history (all women) to have won the "Grand Slam Boxed Set", consisting of every Grand Slam title (the singles, doubles and mixed doubles). Court, however, is the only one in tennis history to complete a Multiple Grand Slam set, twice, in all three disciplines: singles, women's doubles and mixed doubles. Uniquely, she won all 12 as an amateur and then after a period of retirement, returned as a professional to win all 12 again. Court is also one of only six tennis players ever to win a Multiple Grand Slam set in two disciplines, matching Roy Emerson, Martina Navratilova, Frank Sedgman, Doris Hart and Serena Williams.