Billie Jean King

Billie Jean Moffitt grew up in Long Beach, California, the daughter of a firefighter. She learned tennis on public courts and was once left out of a junior group photograph because she was wearing shorts her mother had made rather than a white dress. She said later that the moment taught her that the sport was for a certain kind of person, and she decided to change who that was.

She won her first Wimbledon title in doubles at 17 and went on to win 39 Grand Slam titles across singles, doubles and mixed doubles. But her influence lay in what she did off court. In 1970 she and eight other players broke away from the tennis establishment to start their own circuit for a symbolic one dollar contract each. In 1973 she founded the Women's Tennis Association and persuaded the US Open to pay women the same prize money as men.

That same year, at 29, she played the 55-year-old former champion Bobby Riggs, who had boasted that any man could beat any woman. Ninety million people watched her win in straight sets.

In 1981 a former partner sued her, making her the first prominent female athlete to be publicly identified as gay. She lost almost all her endorsements within a day. She kept working, and decades later was awarded the Presidential Medal of Freedom. The US Open is now played at a tennis centre that carries her name.