29 July 2010 Last updated at 03:22 ET

Michael Morpurgo on War Horse and beyond

By Tim Masters Entertainment correspondent, BBC News

Morpurgo has written more than 100 books

With Steven Spielberg about to film War Horse and a stage production of Farm Boy opening in Edinburgh, things are looking good for the author Michael Morpurgo.

The former children's laureate is no stranger to stage or screen adaptations of his books, though few have had the galloping success of War Horse.

The West End hit transfers to Broadway in March 2011, with Spielberg's movie version due out the following August. The cast includes Emily Watson, David Thewlis, Benedict Cumberbatch (currently in TV's Sherlock), Peter Mullan and Jeremy Irvine.

The book tells the story of a farm horse, Joey, who gets separated from his owner and ends up in the trenches of World War I.

What's astonishing is that War Horse made it this far at all. Morpurgo, who wrote the book in 1982, admits it did nothing spectacular for years.

"It nearly won a prize but failed. It was translated into three or four languages. It was published in America and didn't succeed. It stayed in print - just about - for about 25 years. It simply was not a book that anyone really knew about or cared about."

'Spellbinding' Spielberg

All that changed when it came to the attention of the National Theatre, which was on the look-out for an animal-centric drama. The show opened in 2007 to widespread acclaim.

And then Hollywood came knocking on the stable door.

"The Spielberg thing was extraordinary," says Morpurgo. "It worked unbelievably quickly. The deal was done within weeks and the film is going to be made within months."

Morpurgo met Spielberg to discuss the project, and has been kept in the loop as the screenplay (by Lee Hall and Richard Curtis) has developed.

Farm Boy plays at Edinburgh in August with John Walters (left) and Matt Powell

"Steven Spielberg was wonderfully engaging and inquisitive about the whole history of it," Morpurgo recalls. "It was the most spellbinding thing to sit across the table from one of the world's great storytellers."

The 66-year-old author has high hopes for the big screen War Horse: "I'd like it to be the iconic movie of World War I since All Quiet on the Western Front or Oh! What a Lovely War."

Has Morpurgo been surprised by the novel's slow-burning success?

"Am I little surprised?" he answers, with a hint of disbelief at the question. "Yes, I'm a little surprised, but I'm also relatively pleased."

Tractor tale

The book Farm Boy is a "sequel" to War Horse in that it continues the story of Joey after World War I.

Morpurgo, however, isn't fond of sequels: "I don't like going back to to the same field to graze."

But he was persuaded to revisit Joey's story by the illustrator Michael Foreman - who suggested a story about how tractors changed the face of farming.

Michael Morpurgo

• Born in 1943
• Worked as a primary school teacher
• Founded the charity Farms For City Children in 1976
• Has written more than 100 books - Private Peaceful was the 100th
• Other books include: Why The Whales Came, The Butterfly Lion, Kensuke's Kingdom, The Amazing Story of Adolphus Tips, An Elephant in the Garden

"I'd also had a few letters from kids asking what happened to Joey when he comes back from World War I? How did he manage back on the farm?"

More than 30 years ago Morpurgo and his wife Clare set up Farms for City Children in Devon, which gives children the opportunity to work with animals.

"I'm in the wonderful, privileged position of being able to witness this enthusiasm that urban people seem to have when they first come into the countryside," says Morpurgo.

The stage version of Farm Boy - which opens in Edinburgh next week - is a more modest production than War Horse.

"If you went in with the expectations of the immense complexity of the lighting and design and amazing puppets of War Horse then you would be disappointed," says Morpurgo.

"This is a miniature portrait but it's beautifully crafted - all you have on stage is this wonderful old tractor and two people - they take several roles. It's how theatre should be done."

Morpurgo hasn't adapted these recent stage or screen versions of his books because after some earlier attempts he discovered he "really wasn't very good at it".

But there is interest in the film rights to other books such as Private Peaceful (another story from World War I).

And it would be surprising - as the 100th anniversary of the sinking of the Titanic approaches - if no-one wanted to make a version of Kaspar: Prince of Cats, the story of a cat at the Savoy Hotel who ends up on the doomed luxury liner.

Both Private Peaceful and Kaspar contain powerful emotional punches that pull the rug from under readers of all ages.

"Life catches us out," admits Morpurgo. "I know perfectly well as a father and grandfather that life is complicated and there are sadnesses and there are joys, and I reflect those in my stories.

"What I don't try to do is talk down to children and pretend that everything works out and it's all right. I think we must write about those things not in a way that is traumatic, but in a way that touches their hearts."

Farm Boy is on at the Edinburgh Suite, Assembly Rooms, Edinburgh, from 5 - 30 Aug prior to an autumn UK tour.