Born in Michigan on September 26, 1981. (Age: 34)
GRAND SLAM CAREER: 22 wins - Australian Open (2003, 2005, 2007, 2009, 2010, 2015); French Open (2002, 2013, 2015); Wimbledon (2002, 2003, 2009, 2010, 2012, 2015, 2016); U.S. Open (1999, 2002, 2008, 2012, 2013, 2014)
* Williams is now level with Germany's Steffi Graf with the most grand slam singles titles in the professional era, although Margaret Court has 24.
* One of five women, after Maureen Connolly, Margaret Court, Martina Navratilova and Steffi Graf, to hold all four grand slam titles at the same time.
* Williams also owns 13 women's grand slam doubles titles with older sister Venus and has won four Olympic gold medals: singles (2012), doubles (2000, 2008, 2012).
MAKING HER NAME
Learned to play the game with Venus in Compton, California.
Both were coached by their father Richard.
Turned professional in September 1995.
Won her first WTA Tour title in Paris in 1999, beating Amelie Mauresmo in the final.
Defeated Martina Hingis in the U.S. Open final in 1999, becoming the first African-American woman to win a grand slam singles title since Althea Gibson in 1958.
TENNIS CAREER
* Failed to make another grand slam final until 2001 when she lost in the U.S. Open final to older sister Venus.
* Missed the 2002 Australian Open with injury then embarked on an incredible run that included winning five of the next six slams and losing in the semi-finals of the 2003 French Open.
* Career affected by injury over the next four years, winning two Australian Open titles in 2005 and 2007 but failing to advance beyond the quarter-finals at the other three.
* Won U.S. Open in 2008 to break the grand slam drought, having not won a major title since the 2007 Australian Open.
* At the 2009 U.S. Open, Williams was fined $175,000 and placed on a two-year probation for unsportsmanlike behaviour after being defaulted in the semi-final against Kim Clijsters.
* Joined Billie-Jean King on all-time grand slam list in sixth with 12th major title at 2010 Australian Open.
* Missed U.S. Open in 2010 because of medical complications after cutting her foot on glass while celebrating her win at Wimbledon.
* In 2011, underwent surgery after a life-threatening blood clot was detected on her lung. Made the U.S. Open final but lost to Australia's Sam Stosur.
* Won Wimbledon title in 2012 and followed that with Olympic gold on the same grass courts, beating top seed Victoria Azarenka in semi-finals and third seed Maria Sharapova in final.
* Won fourth U.S. Open title in 2012, beating Azarenka in the final.
* Won second Roland Garros title in 2013, one of 10 titles she lifted that year to reclaim world's top ranking.
* Claimed seven titles in 2014, including her sixth U.S. Open, which was her third in succession, to join compatriots Chris Evert and Martina Navratilova on 18 grand slam wins.
* Defeats Maria Sharapova in the 2015 Australian Open final to secure her 19th grand slam title.
* Despite battling a bout of flu, wins a third successive major title and 20th overall by overcoming Czech left-hander Lucie Safarova in the French Open final.
* Claimed so-called 'Serena Slam' by winning sixth Wimbledon crown to hold all four majors for the second time in her career. Seemed poised to secure a calendar grand slam at the 2015 U.S. Open but lost to Italy's Roberta Vinci in semi-final.
* Denied again in the 2016 French Open final, this time by Spain's Garbine Muguruza.
* Has been year-end number one in the rankings from 2013-15.
