Harry Potter and the Deathly Hallows Part I will premiere tonight, marking the beginning of the end for the most successful film franchise in history. Daniel Radcliffe, Emma Watson and Rupert Grint will join fellow cast members on the red carpet in Leicester Square.

JK Rowling's final book has been split into two films, with the second instalment released next summer, because the writers were unable to cram all of the action into two hours.

"When we began working on the screenplay, it became clear we would have to omit too much to do justice to Jo's book in one film," said producer David Heyman. 

The seventh film promises to be the darkest yet. The characters - Harry, Hermione and Ron - are far from Hogwarts and their lives are under threat from evil forces.

"They are always on the move and, worse, they are being hunted, so they don't know who to trust. But the stakes are high so they have to be brave," said Watson, while Grint added: "Away from the safety of Hogwarts and the protection of their parents and teachers, anything can happen. They can be attacked at any moment, which gives the film a different energy."

Joining the likes of Helena Bonham Carter (Bellatrix Lestrange), Jason Isaacs (Lucius Malfoy) and Ralph Fiennes (Lord Voldemort) are new cast members Rhys Ifans as Xenophilius Lovegood and Bill Nighy as Minister of Magic Rufus Scrimgeour.

Nighy was delighted to get the call-up: "For a while, I thought I would be the only English actor of a certain age who wasn't in a Harry Potter film."

The film is released nationwide on November 19, with Part II scheduled for release in July 2011.

They were filmed back-to-back and Radcliffe said the cast were in tears after the final scene. "We were all really devastated. It was really very sad - a weird, weird feeling. We were crying quite a lot."

According to Watson, Deathly Hallows is the best film yet. "This is the last Harry Potter story and I really wanted to do it justice and go out with a bang. And I was blown away - it was above and beyond all of my expectations."

Source: http://www.telegraph.co.uk/culture/harry-potter/8124417/Harry-Potter-and-the-Deathly-Hallows-Part-I-the-world-premiere.html