Britney Spears, who turned 35 on Dec 2, revolutionized teen pop in the 1990s. Before she was 20, Britney became the best-selling teenage artist of all time. Her first album `Baby One More Time' in 1999 became the best-selling album by a teenage artist. But after her first four chart-busting albums, Britney's personal life spun out of control. She married her childhood friend Jason Alexander in January 2004, but the marriage was annulled 55 hours later as she `lacked understanding of her actions.' It was the shortest celebrity marriage. In September 2004, she married dancer Kevin Federline with whom she had two sons - Sean Preston Federline (Sept 2005) and Jayden James Federline (Sept 2006). The couple were divorced in July 2007. The year 2008 was very tough for the Princess of Pop as she lost visitation rights to her two sons and Federline was given sole custody of the boys. Britney had to be admitted to a psychiatric hospital. She slowly recovered. Britney has sold over 100 million albums and over 100 million singles.