X-Men stars were greeted by thousands of fans
Thousands of fans packed Leicester Square as the stars of X-Men 2 arrived for the film's world première.
Sir Ian McKellen, dressed from head to foot in white, was joined by co-stars including Famke Janssen, Rebecca Romijn-Stamos, Anna Paquin and Kelly Hu.
McKellen, who plays Magneto in the comic book superhero adaptation, said X-Men 2 featured "the most glamorous cast ever assembled".
The gay actor joked that he had found it distracting to work with Hugh Jackman and James Marsden, but that while working all day with Halle Berry he "didn't turn a hair".
Oscar-winning actress Berry - who plays Storm - was not at the big event, opting instead to attend the Scottish premiere next Tuesday, which will raise money for diabetes research.
Star Trek actor Patrick Stewart, who plays mutant leader Professor Xavier in X-Men 2, said the film was better than its predecessor.
He said: "I always felt the first movie was an expensive extended trailer which was there to introduce the X-Men and their world.
"This film swooped straight into the story and it's just terrific."
Scottish actor Alan Cumming revealed that he and Sir Ian whiled away their time filming in Canada by visiting a nudist beach.
He said: "Ian wanted to go and he needed someone to go with him so I said yes.
"I was quite curious so I went along with my dog and it was really quite nice."
X-Men 2, released in most countries between 30 April-2 May, is expected to be one of the biggest films so far this year.
The first film, adapted from the Marvel comic series that began in the 1960s, took almost $300m (£184m) worldwide in 2000.
X-Men 2 goes on general release in the UK on 1 May.