By Tom Bishop
BBC News Online entertainment staff
Actor Marlon Brando, who has died in Los Angeles at the age of 80, had enormous impact on late 20th Century screen acting in both his performance and technique.
Brando's naturalistic performances made him a hero to fellow actors
Pivotal roles in films such as The Wild One and the Oscar-winning On the Waterfront revealed Brando's intense brooding naturalism, which many contemporary actors have tried in vain to emulate.
"People always ask me who was the most influential guy to us young guys back then," actor James Caan said earlier this year.
"Anyone who doesn't tell you Brando was the man, they're lying."
Nineteen-year-old Brando began studying with acting coach Stella Adler at Elia Kazan's Actors Studio theatre workshop in New York in 1943.
A devotee of the Russian Constantin Stanislavsky, Adler pioneered his "method" style of character assimilation in the US.
This technique was to revolutionise stage and film work with a new sense of realism, Adler telling her students: "Don't act. Behave."
Bringing intense emotion and raw improvisation to his performance, Brando's talent was said to have outshone his classmates, who included Marilyn Monroe, Shelley Winters and Rod Steiger.
Paul Newman, who was also learning to act at that time, said: "I'm angry at Marlon because he does everything so easily.
"I have to break my ass to do what he can do with his eyes closed."
James Dean was said to have worshipped Brando, copying everything about him from his stance to his mumbling way of speaking.
Robert Tanitch, author of a book, Brando, said the actor had a huge influence when he burst onto the 1950s acting scene.
"Diction used to be thought important - he made acting seem natural by overlapping and hesitating," Tanitch said.
"All the great film actors since On the Waterfront are heavily influenced by Brando. And when he appeared in The Godfather, all those actors in The Godfather said he was the godfather of screen acting."
Coupled with his edgy sexual presence, Brando's talent established him as both a Hollywood icon and America's key disciple of method acting.
Film critic Jason Solomons said it was Brando's experiments in method acting which helped him make such a huge impact on screen.
"What he did was change acting forever - screen acting, film acting. No-one had ever done, no-one had tried to do, what he did.
"He was an extremely brave experimenter. He would do it himself - no director would need to tell him to do it," Mr Solomons continued.
He married his powerful performance to shrewd roles, such as his portrayal of Don Corleone in The Godfather, for which he won his second Oscar in 1972.
Director Bernardo Bertolucci (left) said Brando could be a "monster"
But by middle age his edgy performances were overshadowed by his apparent laziness and fading interest in acting.
Bernardo Bertolucci, who directed Brando in 1974's Last Tango in Paris, described Brando as "an angel as a man, a monster as an actor".
And Brando himself would later say of acting: "Acting is the expression of a neurotic impulse. It's a bum's life. Quitting acting is a sign of maturity."
He said he only made movies for the money. "Acting is an empty and useless profession," he stated.
Despite his disillusion, every few years another male actor - from Mickey Rourke to Russell Crowe to Johnny Depp - is crowned "the new Brando" by critics. All have yet to live up to the title.