Cast in her first film Le Petit Bougnat at age 14, she quickly became quite a hit too with French theatre audiences and became the first person to be invited to join the prestigious Comédie Française company without graduating from the Conservatoire. She left in 1974 to concentrate on a movie career which has brought her four César Awards and two nominations for best actress Oscars.
She's worked in English language movies like The Driver and Nosferatu, as well as the odd German film. A close friend of Sharon Stone, Isabelle has had high profile relationships with fellow actors Warren Beatty and Daniel Day-Lewis, as well as an engagement to musician Jean-Michel Jarre. French TV show audiences voted her the second most beautiful woman behind only Monica Bellucci as late as 2004.