Best-selling author J.K. Rowling joined the young stars of the Harry Potter movies on Tuesday at the London premiere of Harry Potter and the Order of the Phoenix, the fifth in the seven-part franchise.
Organizers recreated the atmosphere of the fictional Ministry of Magic, where much of the action in the latest film takes place.
Hundreds of Potter fans, many of them young girls, assembled in Leicester Square in torrential rain and thunder and chanted "Harry, Harry, Harry" to see the teenaged stars on their way into the Odeon Cinema. Some had camped out overnight.
Daniel Radcliffe, who plays the boy wizard, clearly enjoyed the female attention.
"I can't complain. It's rather wonderful, really," he said.
Radcliffe, Emma Watson (Hermione Granger) and Rupert Grint (Ron Weasley) lead the cast, along with Imelda Staunton, who steals the scenes she appears in as the sinister control freak Dolores Umbridge.
Rowling said she shared the view of many critics that "Phoenix" is the darkest of the Potter films so far.
Harry Potter and the Order of the Phoenix follows Harry as he gathers a band of fellow magicians at Hogwarts and prepares them for the battle that he knows lies ahead.
It has been described by critics as darker than previous Potter movies, focusing more on the students' inner journeys. Reviews have been mixed, with some critics confessing confusion over the plot.
The London premiere came five days after a red-carpet screening in Tokyo but is likely to be the biggest of the film's regional launches, with most of the main cast due to attend along with a host of British celebrities
It kicked off a monthlong outbreak of Pottermania, with the release of the seventh and final book in the Harry Potter series set for July 21.
Fans are speculating which characters will die at the end of Harry Potter and the Deathly Hallows after Rowling said she would kill off at least two of them.
Rowling indicated that the final book would indeed be the last Harry Potter, and, when asked if she had been tempted to change her mind, she said: "No, it is really what it was always planned to be."
More than 325 million copies of the first six books have been sold worldwide, helping to turn Rowling into the first dollar-billionaire author. Online pre-orders for the final installment have already broken records.