Tyler achieved international recognition as a result of her portrayal of Elf maiden Arwen Undómiel in the Lord of the Rings film trilogy. She has appeared in an eclectic range of films, including the 2004 comedy Jersey Girl, the indie film Lonesome Jim (2005), the drama Reign Over Me (2007) and big-budget studio films such as Armageddon (1998), The Strangers (2008) and The Incredible Hulk (2008).
Since 2003, Tyler has served as a United Nations Children's Fund (UNICEF) Goodwill Ambassador for the United States, and as a spokesperson for Givenchy's line of perfume and cosmetics.
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[5] 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.
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Tyler attended the Congressional Schools of Virginia, Breakwater School and Waynflete School in Portland, Maine, before returning to New York City with her mother at the age of 12. She went to York Preparatory in New York City for junior high and high school, after her mother researched the school to accommodate Tyler's ADHD. She graduated in 1995, and left to continue her acting career. When asked about the way she spent her early life, Tyler said: "For me, I didn’t get much of a childhood in my teen years because I’ve been working since I was 14. But that also kept me out of trouble. When everybody was doing acid and partying like crazy, I was at work on a movie in Tuscany ... having my own fun, of course, but it was a different kind of thing. I have no regrets. I love the way my life has gone."
At the age of 14, Tyler received her first modeling job with assistance of Paulina Porizkova who took photos of her that ended up in Interview magazine. She later starred in television commercials. However, she became bored with her modeling career less than a year after it started, and decided to go into acting. She never took acting lessons. Tyler first became known to television audiences when she starred alongside Alicia Silverstone in the music video for Aerosmith's 1993 song "Crazy".
Tyler made her feature film debut in Silent Fall in 1994, where she played the older sister of an autistic boy. In 1995, she starred in the comedy drama Empire Records.Tyler has described Empire Records as "one of the best experiences" she has ever had. Soon after, she landed a supporting role in James Mangold's 1996 drama Heavy as Callie, a naive young waitress. The film received favorable reviews; critic Janet Maslin noted: "Ms. Tyler ... gives a charmingly ingenuous performance, betraying no self-consciousness about her lush good looks."