David Walliams: Roald Dahl and me

Little Britain star David Walliams, whose children's book is on the shortlist for the Roald Dahl prize, describes how he fell under the influence of the late author

Before I started writing my first children's novel, The Boy in the Dress, I made a big mistake. I decided to re-read some of the books I had loved as a child. I wanted to try to gauge the right tone for a book for children, after years of co-writing an adult comedy show. I devoured Stig of the Dump, Peter Pan, Alice in Wonderland, The Lion, the Witch and the Wardrobe and – my absolute favourite – Charlie and the Chocolate Factory. This last one instantly made me want to give up writing. It was perfect.

I started reading more and more of Dahl's stories. The Twits, Danny the Champion of the World, The BFG, George's Marvellous Medicine, The Witches and Fantastic Mr Fox. Soon I realised that they were all perfect in their own way. What really surprised me was how different each was from the others; there was no apparent formula. For example, the events depicted in Danny the Champion of the World could happen in the real world, whereas those in The BFG couldn't. So why is Roald Dahl, 20 years after his death and 40 years after he wrote some of his best-known works, one of the most enduringly popular children's authors?

First, I think it's because he understood that children respond to stories where they are empowered. Harry Potter may be the most extreme example of this, but Dahl always empowers his child characters with masterful subtlety. He never gives them magical powers or makes them secret agents. Charlie lives in poverty but finds a golden ticket; George happens upon a recipe that makes his loathsome grandma change size; Danny has to drive his father's car through the night. Dahl empowers them enough, but never too much. It is interesting that he leaves George unable to remember his magical recipe.

Cruelty is something Matt Lucas and I have always been drawn to in Little Britain. Whether it's Marjorie Dawes bringing misery to the lives of her "Fatfighters" group, or Carol "Computer Says No" Beer enjoying being phenomenally unhelpful to children and the elderly. Dahl is the master of cruelty. Witness what happens to all those rotten children in Willy Wonka's factory. Augustus Gloop falls into the chocolate river and is sucked through a giant pipe, Veruca Salt is attacked by squirrels and disposed of down a rubbish chute, Violet Beauregarde (what genius character names!) is turned into a giant blueberry and Mike Teavee is shrunk. Reading it as a child, I was pretty sure they had been killed, and looking at it again I got the feeling that may have been what Dahl wanted. The children are glimpsed again later in the story, but it feels like an afterthought to appease concerned parents. In his story, George effectively kills his grandmother. She is certainly dead at the end of the book. This lack of conventional morality is extremely compelling for young readers, who feel as though they are entering a thrillingly dangerous world.

When I was growing up in the 1970s and 1980s, Roald Dahl was a regular on television. He was certainly famous enough for Peter Cook to parody him. In Cook's sketch, the Dahl character sits too close to the fire and his blanket goes up in flames. Not only did Dahl appear on TV introducing adaptations of his often sublime Tales of the Unexpected, he was also a fixture on Saturday-morning children's television.

In a way, though, he was not a great ambassador for his work. As a child I was quite scared of him. Dahl was unfeasibly tall (6ft 6in), bald, and dressed like an old professor. He came across as an eccentric and cantankerous uncle, and didn't seem to have much warmth for the children who would telephone the shows with their questions. He was an outsider who sat alone in his shed all day, dreaming up more and more wicked stories. Stories that you were absolutely desperate to read.

His narratives are surprisingly anarchic too. The stories of his I hadn't read as a child surprised me as an adult. There is nothing prescriptive or predictable about them, with little sense of narrative rules. Nothing reassuring. So many children's stories want to have everything in their rightful place. Not Dahl's. Indeed, The BFG reads like a dream narrative, with the Queen making an appearance halfway through to save the day. In The Twits, a blacker-than-black comedy about an old couple who loathe each other, talking monkeys show up. Tim Burton changed the ending of Charlie for his film version, adding a scene where Willy Wonka experiences family life for the first time with Charlie, his parents and grandparents. Burton forced a kind of redemption on Willy Wonka, but Dahl doesn't feel the need for a happy ending. Instead the book ends with Wonka whisking Charlie and his grandpa off in his great glass elevator.

The economy of Dahl's writing takes my breath away. He includes precious few references to people, places, or products, which makes his books timeless. A lesser talent like myself can't help mentioning The X-Factor and pickled-onion Monster Munch. Dahl rarely uses metaphor, though when he does it is devastatingly effective. In George's Marvellous Medicine he compares the grandmother's smile to that of a snake that is just about to bite you. Dahl also has a very clever way of making the reader feel as though he or she is being addressed directly. "This is Charlie", he writes. "Look, he's waving at you". It is as if Dahl is in the room reading to you. Underneath these lines is an illustration of Charlie waving. I had absolutely no hesitation in stealing this idea for my new children's novel, Mr Stink, when introducing my characters.

Nor was that the only thing I stole. I also stole Quentin Blake to illustrate my writing. Well, I didn't literally steal him by snatching him in the street, bundling him in the boot of a car, and telling him he'd never see his family again unless he started drawing. Of course I would have been forced to do that had he refused to work with me. No, I stole the idea of collaborating with Quentin. It is a little known fact that the first version of Charlie and the Chocolate Factory was not illustrated by Mr Blake but by Joseph Schindelman. Now it is difficult to imagine a Dahl book without Blake's illustrations. What Quentin does so brilliantly is give a sense of what Dahl's characters look like without defining them exactly. The illustrations are impressionistic. Watching a film of one of Dahl's books can be disappointing, as a film never asks you to add your imagination in the way a book does. For me, brilliant though both actors were, Willy Wonka is neither Gene Wilder nor Johnny Depp, but somewhere deep in Quentin's deceptively simple black-and-white drawings. You also sense that Dahl was so enthused with his collaborator that his writing increasingly made room for Quentin's illustrations. By the time of George's Marvellous Medicine, the drawings are not illustrating the story but rather an integral part of the storytelling.

Children are the toughest audience. If they find something boring they say so. If they don't like a book they will simply stop reading it. At school you might be forced to read Shakespeare or Milton or Dickens. Twenty years after his death, the beauty of Dahl's status as an author is that his work is regarded as populist entertainment, which places him just outside the "great literature" bracket. Future generations of children will carry on reading his books simply because they want to, not because they have to, for the pure pleasure of luxuriating in Dahl's imagination. What more could any writer ask for?

David Walliams's first novel for children, 'The Boy in the Dress' has been nominated for the Roald Dahl Funny Prize. His latest book, 'Mr Stink', illustrated by Quentin Blake, is out this week. The Roald Dahl Funny Prize is run by the charity Booktrust and awards the funniest books for children. See www.booktrust.org.uk