Serena is undoubtedly one of the best tennis players the world has ever seen.

She won her first Grand Slam at the age of 17 and has gone on to win a total of 11 grand-slam singles titles.

But she has been touched by tragedy too, in 2004 she slipped into a deep depression after the murder of her eldest sister, and she wondered whether she would ever want to play tennis again.

Last month Serena released her autobiography, an honest account of her life from learning to play tennis in the ghettos of LA to becoming a world champion. Serena chats to Holly and Phil about her rise to fame.

Serena was brought up in Compton, one of the most violent neighbourhoods in the United States. Determined to build a different kind of life for his family, Serena's dad Richard decided his daughters should play tennis.

And so it was that at the age of three, Serena had her first tennis lesson. “I remember my dad telling me, 'Just look at the ball, Serena'. I think that was my first memory of playing tennis."

Right from the start it was Venus who showed real talent: “She cast a big shadow, I'll say that. She was taller, prettier, quicker, more athletic. And, she was certainly nicer." But it never changed the way Serena looked up to Venus.

Commentators dismissed Serena as just Venus' little sister, failing to believe that there could be two world champions in the same family. But Serena proved them wrong. In 1999, at the age of 17, she had risen to number 8 in the WTA rankings and later that year won the US Open, her first Grand Slam victory.

In her tennis history she has faced Venus in 23 professional matches dating all the way back to 1998: "Our victories our always shared."

In November 2009 Serena took the number 1 spot in the WTA rankings for the fifth time in her career. She is the reigning Australian Open and Wimbledon Champion, and the reigning Australian Open, Wimbledon and US Open Doubles Champion.