He played book-burning fireman Guy Montag in author Ray Bradbury's 1966 film, Fahrenheit 451. That year, he received an Academy Award nomination and a Golden Globe Award for Best Supporting Actor.
At age 18, he became the youngest actor to be accepted at the Austrian state theatre.
In 1962, he appeared in the groundbreaking French New Wave film, Jules et Jim.
He was married to Anne Power from 1954 to 1968. His children are Eleanore and Felix Florian.
He starred in Fahrenheit 451 with Julie Christie.