Venus and her younger sister Serena (who is 18 months younger) grew up in Los Angeles, where they lived with their parents and three older sisters. They both started playing tennis when they were just four years old. The Williams family didn't have very much cash, so they couldn't buy any new tennis balls. Instead they played with old balls they found. The two sisters couldn't afford expensive tennis lessons at a ritzy country club either, so their dad, Richard, bought a book on tennis and taught them himself. The two sisters smashed balls on beat-up, old tennis courts for up to six hours a day while their dad, who had never played much tennis before, read instructions from his book. The two sisters made tennis history on September 8, 2001 when they became the first sisters to play each other in a US Open final in more than 100 years. It was also the first time two African Americans had played each other in the final. Since then, Venus and Serena have been the most dominant players on the women's circuit.