Serena Williams

14 Age of her professional debut Ken Levine/Getty Images Age of her professional debut

Serena Williams played her first match on the Women's Tennis Association Tour at the 1995 Challenge Bell in Quebec City, Canada. The youngster crashed out of the first round after playing less than one hour when she lost to the then world No. 149 Annie Miller.

23 Grand slam singles titles Julie Jacobson/AP Grand slam singles titles

After winning her first grand slam title at the US Open in 1999, Williams would go on to win 22 more – seven at Wimbledon, three at the French Open, seven at the Australian Open and five more at the US Open. She sits just one short of Margaret Court’s all-time record of 24. Serena has also won 14 doubles titles, all with her sister, Venus, and two mixed doubles titles.

31 Times Serena has played Venus Kamran Jebreili/AP Times Serena has played Venus

The two sisters grew up playing together on public courts in Compton, Los Angeles, and the pair have continued their rivalry on the biggest stage – they met nine times in grand slam finals. Despite being younger than her sister, Serena Williams boasts the better record, having won 19 of the matches they played against each other.

$94M Career prize money Clive Brunskill/Getty Images Career prize money

No female tennis player has earned anywhere near as much as Serena Williams during her career – she’s totaled more than double Venus Williams, who is the second highest female earner. Her most dominant year came in 2013, when she won $12.4M in a single season, smashing the previous record of $7.9M.

$340M Estimated off-court earnings Scott Barbour/Getty Images Estimated off-court earnings

Williams’ off-court revenue has dwarfed her record-breaking