by Sanchia Berg
In France, Le Petit Nicolas is a national treasure.
Created by the author of Asterix, Rene Goscinny, and the cartoonist Sempe, Nicolas is an eight-year-old boy who is always - unintentionally - getting into trouble, together with his gang.
He first appeared in story form in 1959 and hasn't been out of print since.
Some years ago, Rene's daughter Anne found some unpublished stories amongst her father's archives. She persuaded Sempe to draw new illustrations.
Those collections have sold a million copies since 2006 - the latest selection was published earlier this month.
In all, about 10 million Nicolas books have been sold worldwide.
So it's not surprising that to celebrate Nicolas's 50th birthday this spring, the Hotel de Ville in Paris has an exhibition about him and in September, a major feature film based on the books will be released in France.
Nicolas is available in English and while the British publisher says they do sell well, the books are not generally known in the UK.
Perhaps that is because we have naughty schoolboys of our own - the classic Just William and, of course, Horrid Henry.
Around 13 million Horrid Henry books have been sold, and they haven't even been published in the US yet.
Francesca Simon created Horrid Henry. She spent part of her own childhood in France. When asked what she thought of Nicolas, "charming" was her verdict.
She saw similarities with Horrid Henry in that neither character intends to be bad.
"I give the illusion of great wickedness but there's never a story where Horrid Henry climbs on the roof with a lighted match," she said.
"His horrible wickedness consists of plotting where he can sit in the car.
"The Nicolas books also give an illusion of greater wickedness than in fact happens."
Horrid Henry operates in a far more restricted sphere, of course.
While Henry gets to sabotage the school nativity play, Nicolas smokes a cigar, plays truant, runs away from home and nearly blows up a friend's house with a chemistry set.
These are all adventures you won't find in modern books for this age group because children's lives have become far more constrained.
Perhaps that's why they appeal to the three seven-year-old boys I interviewed - they all found them very funny.
While neither Horrid Henry nor William reflect on events, Nicolas does.
And there is a knowingness, an archness of tone in his observations which can be irritating. That could help explain why the books haven't really taken off here.
To the French, ironically enough, Nicolas seems rather British.
That's the view of Aymar Du Chatenet, publisher of the latest collections of stories and curator of the Hotel De Ville exhibition.
He says that Nicolas is dressed in a British way and that he has - to the French reader - a rather British sense of humour.
He hopes that more British readers will discover him. And maybe they will - there's certainly been a trend in the UK to republish children's books of the 1950s and 60s.
The Tiger Who Came to Tea has never gone away, but This Is London and Harry the Dirty Dog are back in the bookshops now.