Tyler was born Liv Rundgren at Mount Sinai Hospital in New York. She is the first-born daughter of Bebe Buell, a model, singer, and former Playboy Playmate (Miss November 1974), and Steven Tyler, the lead singer of Aerosmith. Her mother named her after Norwegian actress Liv Ullmann, after seeing Ullmann on the cover of the March 5, 1977 issue of TV Guide. She is of Italian, German, Polish, Russian and English ancestry on her father's side and also has three half-siblings: Mia Tyler (born 1978), Chelsea Anna Tallarico (born 1989), and Taj Monroe Tallarico (born 1992). Her maternal grandmother, Dorothea Johnson, founded the Protocol School of Washington.
At birth, Buell claimed that rock star Todd Rundgren was Tyler's biological father. At age nine, Tyler discovered that she was Steven Tyler's daughter after meeting him and noticing a resemblance she shared with his other daughter, Mia. When she asked her mother about the similarity, the secret was revealed. The truth about Tyler's paternity did not become public until five years later, in 1991, when she changed her name from Rundgren to Tyler, but kept the former as a middle name. Buell's alleged reason for the initial decision was that Steven was too heavily addicted to drugs at the time of her birth. Since learning the truth about her paternity, Liv and Steven have developed a close relationship. They have also worked together professionally, once when she appeared in Aerosmith's music video for "Crazy" in 1993 and again when Aerosmith performed many of the songs in the film Armageddon (1998), in which Liv Tyler starred.
http://en.wikipedia.org/wiki/Liv_Tyler