Andy Giddings - BBC News, West Midlands, Ben Sidwell - BBC Midlands Today and Rosie Eaton - BBC CWR

"It's up there with some of the most important Christmas films for people".

That's the verdict of movie director Debbie Isitt, who puts a hefty slice of the affection for Nativity! down to the starring role Coventry's Holy Family Primary School played.

Celebrating 15 years since it all began Ms Isitt, from Harborne in Birmingham, has returned to the school, which became known as St Bernadette's for the film series she penned.

Admitting she had no idea the film would go on to sustain itself for that long, she said: "I think it's true to say it is part of the culture now for Christmas."

The first film followed a primary school teacher played by Martin Freeman, who gets into festive rivalry with a teacher at another school, played by Jason Watkins.

Following the success of the 2009 movie, Ms Isitt wrote and directed three others in the series and a stage musical.

She said she was "really emotional" to be back at the school and admitted she thought it would be a Christmas movie that "would just come and go like so many do".

"Its amazing that it's still going strong, stronger than ever really," she said.

Several teachers also have fond memories of the filming 15 years ago.

"It surprises me, because you don't think that people will recognise you or even remember," teacher Angie Ward, who had a small part in the film, said.

She said it was "just mind blowing" that strangers still recognise her from the film.

Another teacher, Clare Tompkins, said her daughter successfully auditioned for a role and appeared as a member of the St Bernadette's choir.

But she said her son, who was five at the time, was "just completely stage struck" when he went up before the film crew for his audition.

She said she was invited to sing along with him to help him get over his nerves, but when he still would not sing, the crew stepped in to help out.

"All of the crew were so beautiful, they started singing when Santa got stuck up the chimney with me," she said.

In the end he got an appearance at the end of the film, in the out-takes, "sat there with a little glum face".

But she still said it was "the most incredible experience" and one both her children have "really fond memories of".

Tom McGarrity, then 11, played the part of Zack in the first film and remains very grateful to have been given the role.

He is now a director on a cruise liner and said: "I do not not believe I would have the career I would have now if it weren't for the fact that I got Nativity!.

"Debbie gave us the chance to perform, and honestly I had the best time and I'm so glad I was able to do it."

He said he watches it every year, adding: "Every time I watch it I remember different memories of filming different scenes, of different people, it was just amazing."

Mrs Tompkins has worked at the school for 28 years and said the movie "was a great thing for the city".

She said it put it on the map and "was a real positive because it shows the talent Coventry has, but also showed some of the environments that we have".

Head teacher Grainee Griffiths, agreed and said: "Everybody knows somebody who was in at least one of the films in Coventry and that's what's so special about it."

She said she was always asked about it when she went to teaching conferences and people still come to the school to take photos.

"We're very proud to be known as the Nativity! school," she said.