The inception of WTA Rankings took place on November 3, 1975, with Chris Evert the first No.1.
Evonne Goolagong became the second World No.1, rising to the top spot for two weeks in 1976.
Martina Navratilova became the third World No.1 in 1978. She ended up spending 332 weeks there.
Tracy Austin broke up the Evert-Navratilova domination, spending 21 weeks at No.1 in 1980.
It wasn't until 1987 that the domination would end. Steffi Graf spent a record 377 weeks at No.1.
Monica Seles, a pioneer of power in women's tennis, rose to No.1 for the first time in 1991.
No.2 for years behind Graf, Arantxa Sanchez-Vicario finally got to No.1 for 12 weeks in 1995.
In 1997 history was made, as a 16-year-old Martina Hingis became the youngest ever World No.1.
Another pioneer in the power game, Lindsay Davenport, made it to No.1 for the first time in 1998.
After an absolute fairytale year, comeback kid Jennifer Capriati got to No.1 in the world in 2001.
After winning back-to-back Wimbledons and US Opens, Venus Williams rose to No.1 in early 2002.
But in July 2002, little sis took over from big sis - WTA legend Serena Williams ascended to No.1.
The Williams reign was snapped by Kim Clijsters, who was the first Belgian No.1 in August 2003.
Soon after another Belgian, Justine Henin, rose to No.1 with her classic game in October 2003.
And another player with a gorgeous all-court game - Amelie Mauresmo - ascended to the top in 2004.
An 18-year-old Maria Sharapova became No.1 in 2005. The Russian is the last teenager to be No.1.
Ana Ivanovic's rise to No.1 came on the heels of her first Grand Slam title at 2008 Roland Garros.
Ivanovic wasn't the only Serb to rise to No.1 - Jelena Jankovic also got to the top spot in 2008.
Dinara Safina, one of the hardest-hitters in WTA history, spent half a year at No.1 in 2009.
And Caroline Wozniacki accumulated an incredible 67 weeks at No.1 during 2010, 2011 and 2012.
Victoria Azarenka became the 21st World No.1 in 2012 and is one of 10 players to pass 50 weeks.