He was the goofy, comic genius whose racing mouth and mind left audiences breathless as they tried to keep up with oddball jokes, impersonations and cultural quips.

Robin Williams, star of films as varied as Good Morning Vietnam, Mrs Doubtfire and Dead Poets Society, died yesterday at the age of 63.

As with many of the greatest comics, Williams found that life brought great lows to go with the highs, and he struggled with both alcohol and drug addictions in the 1970s and 1980s.

His press representative, Mara Buxbaum, said he had recently been battling severe depression and police in Marin County, where his body was found at the home he shared with his third wife Susan Schneider, said he died from suicide.

Born in Chicago in 1951, Williams developed a quick wit as a means of overcoming shyness as a youngster and found more self-assurance when he joined his school's drama club.

After leaving he was accepted into the famed Juilliard Academy drama school in New York.

He was a contemporary of Superman actor Christopher Reeve and Frasier star Kelsey Grammer in the mid-1970s, and it was there that he was encouraged to pursue comedy seriously.

A renowned stand-up comedian, he appeared on The Richard Pryor Show and Happy Days before his TV breakthrough in the late 1970s with the hit show Mork & Mindy, with Williams starring as the alien Mork who came to Earth from his home planet of Ork.

The show ran from 1978 to 1982 and spawned the first of numerous well-known Williams phrases - "Na-nu Na-nu", Mork's greeting, and introduced his comic talents to the world.

It was also the first platform for his wildly manic talent for improvisation.

The actor reportedly made so many jokes during filming that gaps were specifically written in to scripts to allow him to improvise and ad-lib.

Hollywood beckoned, but it was not until 1987 that he exploded into life at the cinema, screaming down the airwaves to receive his first Oscar nomination and winning a Golden Globe for his portrayal of the unorthodox and irreverent DJ Adrian Cronauer in the film Good Morning, Vietnam.

Williams brought a different sensitivity to another of his most famous roles, inspiring a generation of soulful youths as English teacher John Keating in the 1989 film Dead Poets Society, telling them: "No matter what people tell you, words and ideas can change the world."

The role garnered him his second Oscar nomination, as well as a Golden Globe nomination; another Academy Award nomination and Golden Globe win came from 1991's The Fisher King.

Williams went on to captivate families around the world when he provided the voice of the Genie in the Disney film Aladdin, before charming his own on-screen family by cross-dressing his way into their hearts in Mrs Doubtfire in 1993, opposite Sally Field, which earned him another Golden Globe win.

It was finally in 1997 that he picked up his one and only Academy Award, winning the Oscar for best actor in a supporting role as psychologist Sean Maguire in the Ben Affleck and Matt Damon-penned drama Good Will Hunting.

But while Williams continued to find success in both television and on the big screen, he revealed in 2006 that he had started drinking again.

Despite this he still found it in him to joke about his condition, saying during a recent tour: "I went to rehab in wine country," he said, "to keep my options open".

The following year he told reporters that people were surprised he was no longer clean, saying: "I fell off the wagon after 20 years and people are like, 'Really?' Well, yeah. It only kicks in when you really want to change."

He won a Grammy in 2003 for the best spoken comedy album, Robin Williams - Live 2002, and once likened his act to the daily jogs he took across San Francisco's Golden Gate Bridge.

There were times he would look over the edge, one side of him pulling back in fear, the other insisting he could fly.

Plans for a sequel to Mrs Doubtfire were reportedly under way in recent months, but it seems likely they will be put on hold or shelved indefinitely in the wake of Williams' death.

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