Daniel Radcliffe has told Harry Potter fans the films would be with them "for the rest of their lives".
Thousands of people flooded into central London to say an emotional goodbye to the hugely popular series at the world premiere of Harry Potter And The Deathly Hallows Part Two.
Stars including Emma Watson and Rupert Grint spent hours on the red carpet, which stretched from Trafalgar Square to Leicester Square, signing autographs for fans. The night ended with author JK Rowling joining the cast and crew on a stage in the square where they addressed fans.
Emma, who wiped away tears, thanked her co-star Rupert for making her laugh while he admitted making the films had been "the best part of my life".
Rowling was also tearful thanking the actors for "the amazing things they did for my favourite characters". Turning to the fans, she said: "Thank you for queuing up for the books for all those years, for camping out in a wet Trafalgar Square."
She then pleaded with the fans, who were chanting 'Thank You' back to her, to stop, saying "No, no, I'm already crying."
Daniel Radcliffe got one of the night's biggest cheers when he told fans: "Each and every person, not just here in this square but around the world who have watched these films for the last 10 years, they will always carry the films with them for the rest of their lives".
Fans had been arriving in London all week for the premiere with many of them camping in the square for days, often dressed as characters from the hit films.
Other cast members who walked up the red carpet included Robbie Coltrane, who plays Rubeus Hagrid, Tom Felton who plays Draco Malfoy and Julie Walters who plays Molly Weasley.