Steffi Graf

A tennis pro at 13, she stayed at the top of the women's tour for a record 377 weeks. Dedication brought her fame and marriage to Andre Agassi has kept her in the spotlight.

Professional tennis star Steffi Graf so dominated her era that she spent 186 consecutive weeks as the top ranked women's player in the world. Over the course of her phenomenal career, she parked for a record 377 weeks in top spot on the Women's tour.

Graf turned professional at the age of 13 and never looked back. During one calendar year, she won all four Grand Slam titles - only the third woman in the history of the game to accomplish this feat. Her fierce dedication to the sport combined with her razor sharp competitive edge has made her one of the most admired and formidable figures in women's tennis, but she also received unwanted help from an unexpected source.

In 1993, a deranged Graf fan stabbed her most threatening competitor, Monica Seles, on the court during a tournament in Germany in order to keep Graf in the No. 1 position. Although Seles' absence from the courts for nearly two years ultimately contributed to Graf's success, the incident was deeply unsettling and left Graf without exciting and challenging competition for some time.

In August 1999, Graf retired suddenly, much to the surprise of many critics. She defended her decision to walk away from the sport saying: "I have done everything I wanted to do in tennis. I feel I have nothing left to accomplish. After Wimbledon, for the first time in my career, I didn't feel like going to a tournament. My motivation wasn't what it was in the past."

However, her love of tennis ensured she did not quit the sport entirely as she made a return in 2005 when she appeared in a one off for the Houston Wranglers in the World Team Tennis (WTT) Pro League. The comeback did not go as she had anticipated as she lost two of her three matches.

Apart from going down 5-4 against Russian Elena Likhovtseva of the Sacramento Capitals, Graf lost the women's doubles when she and her teammate Ansley Cargill were beaten 5-2 by Likhovtseva and Anna Kournikova. Her only success in the event came when she and Mardy Fish beat Mark Knowles and Kournikova 5-3 in the mixed doubles.

"It was a lot of fun. It was not as I expected it to be," said the winner of an impressive 22 Grand Slam titles, who went on to make another appearance in 2009. She played a singles and a mixed doubles exhibition match as part of a test event celebrating a newly installed roof over Wimbledon's Centre Court.

Graf is married to fellow tennis great and Grand Slam champion Andre Agassi with whom she has two children. An ambassador for the WWF, she now devotes much of her time to charity work.