Famous female tennis players as of 2015 include Serena Williams, Venus Williams, Maria Sharapova and Victoria Azarenka. Other female tennis players that have achieved fame in the past are Margaret Court, Billie Jean King, Steffi Graf, Chris Evert and Martina Navratilova.
Serena Williams has won 21 Grand Slam singles tournaments as of November 2015. Her sister Venus has won seven Grand Slam titles. They had many head-to-head matches throughout the 2000s and also achieved several Grand Slam doubles titles as a pair. Maria Sharapova has won five Grand Slam tournaments in her career. She is the only Russian female player to win each of the four Grand Slam tournaments at least once.
Margaret Court won 11 Grand Slam tournaments in the Open era, which began in 1968, and 24 Grand Slam tournaments in total. She dominated women's tennis in the 1960s and early 1970s. Billie Jean King won 12 Grand Slam tournaments in her career. She also defeated male tennis player Bobby Riggs in 1973; her victory brought nationwide attention to women's tennis. Steffi Graf won 22 Grand Slam tournaments during her career. She was the number one player in the 1980s and 1990s, and holds the record for most Grand Slam titles in the Open era, as of November 2015.