The Duke of Cambridge attended the UK premiere of the new Hobbit film on his own on Wednesday, saying his pregnant wife Kate "would have loved to have been here if she could".
William joined the stars of The Hobbit: An Unexpected Journey for the screening in London's Leicester Square while the Duchess, whose pregnancy was announced last week, continued to rest at St James's Palace as she is suffering acute morning sickness.
The Duke of Cambridge attended The Hobbit premiere without his pregnant wife, Catherine
Tessa Street, the general manager of the Odeon cinema which hosted the star-studded event in aid of the Cinema and Television Benevolent Fund, met William as he arrived.
"It's really exciting to have his support for the film and the charity," she said.
"I was a bit nervous being on my own to meet him, but he was very friendly.
"I passed on my best wishes to Kate and he said 'She would have loved to have been here if she could'.
After walking down the special "green carpet" which replaced the usual red for the night, William went inside to meet the cast and was presented with a Hobbit goodie bag to take home to Kate.
She is suffering from the condition known as hyperemesis gravidarum which leaves expectant mothers with constant nausea and regular vomiting.
Over the weekend, her bouts of vomiting intensified to such a degree that William pulled out of the British Military Tournament on Sunday evening to be with his wife.
But although she is still suffering from the condition she may be experiencing less vomiting, so he felt able to attend the premiere.
Meeting the film's stars, he joked with Australian actress Cate Blanchett, who reprises her role as the elf queen Galadriel from the Lord Of The Rings trilogy.
She wore a stunning white backless dress but had donned a black jacket by the time she went into the cinema for the performance.
Talking about the ease of travelling from her native land to New Zealand, where the Hobbit films were shot, he said: "When I go to Australia I'm always winding up the Kiwis and visa versa. You always get a reaction."
Cate Blanchett and Sir Ian McKellen at the premiere in Leicester Square
Ms Blanchett, Sir Ian McKellen and Andy Serkis, who reprised their roles from the Lord of the Rings trilogy, were joined by Office star Martin Freeman, who plays main character Bilbo Baggins in the JRR Tolkien adaptation.
Also braving the freezing temperatures on the green carpet n front of hundreds of screaming fans were showbiz figures including boyband McFly.
Sir Ian, who plays the wizard Gandalf, said it was great to be in London for a film with a strong British presence.
He added: "Its cast is basically British and from the Commonwealth, Tolkien was an English writer, here we are in the capital city and it feels proper."
Olympic long jump gold medallist Greg Rutherford was among the celebrities attending, along with singer Nick Cave.
Director Sir Peter Jackson defended his decision to make the movie trilogy using hi-tech film techniques.
"Twenty four frames per second has been with us since 1927. It's 2012 and I think we have a responsibility as film-makers to use technology to make cinema as exciting as we can," he said.
Sir Ian said he was delighted to return to the role of Gandalf.
"It was lovely to put on the pointy hat again," he said.
And the 73-year-old actor defended Sir Peter's decision to make the film into a trilogy.
"Peter just told us on the last day of filming 'I've got so much material, I can't bear to cut any of it. We'll have to turn it into three films.'
"So we'll have to go back and do a bit more filming in May, back in New Zealand, no grumbles there.
"I've seen the first film and it looks pretty good to me."
He also praised the 3D technology used to make the film.
"I love it in 3D. It's not crude 3D, it doesn't bang out the screen at you. It beckons you in to Middle Earth. It's spectacular."