The Williams sisters are two professional American tennis players: Venus Williams (b. 1980), a seven-time Grand Slam title winner (singles), and Serena Williams (b. 1981), a twenty-three-time Grand Slam title winner (singles), both of whom were coached from an early age by their parents Richard Williams and Oracene Price. Both sisters have been ranked by the Women's Tennis Association at the world's No. 1 position in both singles and doubles. In 2002, after the French Open, Venus and Serena Williams were ranked world No. 1 and No. 2 on singles, respectively, marking the first time in history that sisters occupied the top two positions.

Source: Wikipedia