1D mania hit London as screaming fans greeted the chart-topping boyband at the world premiere of their film, One Direction: This Is Us.
Thousands of fans greeted Louis Tomlinson, 21, Zayn Malik, 20, and 19-year-olds Liam Payne, Harry Styles and Niall Horan as they arrived at the Empire cinema in London's Leicester Square last night.
Some had camped out overnight to ensure they got a prime spot to catch a glimpse of their idols.
"This is unreal," said Styles while Horan added: "This is amazing. We're really excited to be here. We can't believe we are here.
"This is just unbelievable. The last few years have been amazing. This is what we've been dreaming of."
The 3D film, directed by Super Size Me film-maker Morgan Spurlock, is a behind-the-scenes look at the band as they embarked on their mammoth This Is Us world tour.
Styles said the "intimate all-access" film is a love letter to their fans, known as Directioners.
"We made this for the fans. We just want to say a massive thank you to them," he said.
Malik, who posed for photographs with some of the Directioners, added: "The best thing about our fans is their dedication."
The band was put together during the 2010 series of The X Factor and, despite coming third behind winner Matt Cardle and runner-up Rebecca Ferguson, they have gone on to be one of the talent show's biggest success stories.
Simon Cowell, who signed the boys to his Syco record label after their departure from the show, joked that he felt like a proud father.
The TV mogul, 53, who also confirmed reports that he is expecting his first child with New York socialite Lauren Silverman, said: "I feel like a father".
Cowell, who co-produced the film with the group, said: "It has been my dream come true to produce a film. But without their fans, this couldn't have happened. They have the best fans in the world."
X Factor alumni such as Little Mix, JLS, Diana Vickers and Amelia Lily, the show's host Dermot O'Leary and Cowell's right-hand woman Sinitta were also at the premiere, which was streamed live in several countries.
Perrie Edwards, of 2011 winners Little Mix, is dating Malik and said: "I'm proud of my boyfriend but we're really proud of all the boys."
Rolling Stone Ronnie Wood also attended the event with wife Sally Humphreys.
One Direction: This Is Us opens in cinemas on 29 August.
Video: Little Mix talk about One Direction's new film