Williams is donating money from his UK shows to the Prince's Trust charity
Robin Williams has made a triumphant return to the British stage for Prince Charles's 60th birthday comedy show.
Williams, 57, in his first major UK appearance for 27 years, wowed an enthusiastic audience at the New Wimbledon Theatre in south London.
The comic, and co-stars including Rowan Atkinson and Bill Bailey, had Prince Charles, the Duchess of Cornwall and Prince Harry in hysterics at times.
BBC Radio 2 row actor Andrew Sachs appeared as Fawlty Towers' Manuel.
Sachs, who was the butt of lewd jokes made in prank calls by Jonathan Ross and Russell Brand on Brand's radio show last month, appeared in a short sketch alongside his former Fawlty Towers co-star John Cleese - the host of Wednesday night's We Are Most Amused show.
"What is the 11th letter of the English alphabet?" asked Cleese after Sachs had unexpectedly bounded onto the stage dressed, with bow tie and moustache, as his Spanish waiter alter ego.
Prince Charles was joined in the circle by the Duchess of Cornwall and Prince Harry
"Que?" replied Sachs, before falling over in true Manuel style.
It was perhaps the biggest laugh of the night for a part of the show involving 69-year-old Cleese, whose links between the acts were a tad laboured.
The former Monty Python man's recurring joke of getting the next act's name wrong - "Mr William Robins", "Billy Bail" - particularly grated.
The last time the effervescent Williams made a major appearance on the UK stage, he was still starring as Mork in TV sci-fi sitcom Mork and Mindy.
He was also seven years away from his first Oscar nomination for best actor in Good Morning, Vietnam, and 17 years ahead of his best supporting actor Oscar win for Good Will Hunting.
The Royal party met the performers backstage after the show
Unusually for the biggest name on the bill, he opened the show.
Apart from his opening greeting of "Wassup Wales? House of Windsor keeping it real", he left the Royals alone, concentrating more on the recent US election.
On the end of George W Bush's presidency, he said: "He could do stand-up comedy because he has eight years of great material.
"But he cannot go on the speaking circuit - that's a given."
And on the presidential race: "Obama - Fresh Prince. John McCain - Uncle Fester from The Addams Family."
Bill Bailey, with his clever fusion of music and comedy, also had the Royals - who arrived at the Prince's Trust charity evening just a couple of minutes before curtain up - in stitches.
At one point Prince Charles nearly fell off his chair as Bailey imagined, on his keyboard, how the Belarussian national anthem might sound.
Rowan Atkinson also impressed, reprising an old favourite - his bumbling vicar delivering a sermon.
Prince Harry reportedly advised Cleese that he was "auburn... not ginger"
The other British comedians on the bill, Michael McIntyre, Stephen K Amos and Omid Djalili - up-and-coming acts, in relative terms - also shone.
McIntyre, looking forward to his backstage meeting with the prince, wondered: "What happens when a limp handshaker meets a limp handshaker?"
The evening was interspersed with turns from impressionist Jon Culshaw as, among others, Simon Cowell and George W Bush.
And Alistair McGowan and actress Amanda Holden performed a rather lacklustre skit on the difference between newsreading when Charles was born, in 1948, and the present day.
Audiences are so used to the shock tactics of veteran US comedienne Joan Rivers that her act has become decidedly unshocking, but she was good for a few laughs.
She told the audience: "I hate old people and old people that are proud. 'I'm 97 years old,' they say.
"And you smell."
Prince Charles "loves being around comics", said Eric Idle
The finale of the evening came when a seemingly incongruous ballet performance from an ensemble of dancers eventually revealed Cleese's Monty Python co-star Eric Idle to be among their number.
He promptly burst into the song, Always Look on the Bright Side of Life, from Python film Life of Brian, and was joined on stage by a full military band, a male voice choir and all the evening's performers.
But the evening's real show-stopper directly preceded the climax, when Williams and Bailey reappeared for a duet.
It was also the first and only time of the evening that any of the performers really pushed the comedic boundaries in relation to the Royal guests.
The pair had the audience in raptures, singing together - with guitar accompaniment from Bailey - about how difficult it must be for Prince Charles to live in the shadow of the Queen.
"Your momma ain't goin' anywhere, she's gonna hang on to that crown," sang Williams.
"The one thing that ain't on the money is you," concluded Bailey.
Any doubts the comedians may have had that they had gone too far were quashed by the prince himself after the show.
"It was extraordinary," confided Charles to Bailey at a backstage meet-and-greet.
Even more extraordinary was the fact that, as revealed by Bailey, he and Williams had written the song together in just 20 minutes.
"Robin's got a very quick mind, a comic mind," Bailey told Charles.
It is that quick, comic mind which the 1,700 members of Wednesday night's audience will remember long after the feel-good glow left by this night of quality comedy has subsided.
We Are Most Amused will be shown on ITV1 on Saturday 15 November at 2035 GMT and 2220 GMT.
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