Big was born on September 26, 1981, in Saginaw Michigan and is the youngest of five sisters: Lyndrea, Isha, Yetunde, and Venus. Her parents, Richard and Oracene, later relocated to Los Angeles, and the girls grew up in Compton, a rough L.A. suburb.

It was Richard Williams -- now coach and manager of Serena and Venus -- who first introduced young Serena to the sport when he motivated her to start taking lessons at an early age. She began her training in neighborhood courts, where her talent for the sport quickly made its presence known.

When she was only four and a half, Serena entered her first tournament, and from there she went on to win nearly every match she entered at the junior level. Her talent for tennis led to national press coverage and promises of product endorsement deals.

Her sister Venus was also making a name for herself as a pro player, and their father was reluctant to enter them in competitions together, citing the possibility of racial problems and competition among siblings.

In 1993, Serena was enrolled in Rick Macci's Tennis Academy in Florida and the entire family moved to Palm Beach Gardens. And although the World Tennis Association did not recognize players that young, Serena turned pro at 14.

Once she was playing in the big leagues, things got off to a rocky start: Serena suffered a glaring defeat at the 1995 Bell Challenge in Quebec, her first major tournament. In 1997, she was ranked 304th yet beat No. 7 Mary Piercein the second round and No. 4 Monica Seles in the quarterfinals, at a 1997 Ameritech-sponsored tournament in Chicago. With her father's continuous encouragement, Serena continued her upward spiral.

By 1999, Serena was No. 21, after managing to beat sixth seed Irina Spirlea before losing to her sister Venus at the 1998 Australian Open, Serena's first Grand Slam singles event.

Her hard work paid off: The following September, Serena won her first title at the U.S. Open, beating out higher-ranked players like Martina Hingis and Lindsay Davenport The next day, she and her sister won the Ladies' Doubles tournament. There was no question that Serena was en route to becoming one of the greatest tennis players of all-time.

Her stunning performances have vaulted her into the No. 1 position (right above her sister; a first for siblings) and together, she and Venus are the biggest threat in tennis today.

Such success has brought Serena to the attention of producers and agents. In addition to being featured with Venus on a 2001 episode of The Simpsons, she made a cameo in Martin Lawrence's Black Knight and made an appearance in rapper Memphis Bleek's video, "Do My" featuring Jay-Z. And with numerous endorsements such as athletic show company Puma in the works, Serena is not only fulfilling her father's dreams, she's surpassing them.

When she's not practicing, she enjoys surfing, skateboarding, watching cartoons, and playing the guitar. For now, tennis remains a top priority for Serena, as she will undoubtedly make that all-important leap to number one.