Directioners descended into London's Leicester Square in their thousands this evening, for the world premiere of One Direction: This is Us.
Many had camped out overnight in a bid to get a glimpse of Louis Tomlinson, Zayn Malik, Liam Payne, Harry Styles and Niall Horan as they walked the red carpet.
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.
Niall, Louis and Liam spoke to ITV News' Sejal Karia ahead of the screening:
Sejal Karia's report contains flashing images:
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 took time to pose for photographs with fans, added: "The best thing about our fans is their dedication."
Simon Cowell, who co-produced the film with the group and signed the boys to his Syco record label, 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 were joined by the show's host Dermot O'Leary and Cowell's right-hand woman Sinitta at the premiere, which was streamed live in other countries.
Rolling Stone Ronnie Wood also attended the event with wife Sally Humphreys.
"I'm proud of my boyfriend but we're really proud of all the boys," said Little Mix's Perrie Edwards, who is dating Malik.
Twitter UK confirmed that more than 3.6 million tweets were posted on Twitter about One Direction and the One Direction world premiere in London.
One Direction is the most followed UK band on Twitter with more than 14 million followers.
One Direction: This Is Us opens in cinemas on August 29.