The Great Fire of London began in the bakery of Mr Thomas Farriner in Pudding Lane, on September 2, 1666.

The fire burned for four days and gutted the medieval City of London, destroying 373 acres within the old city wall and 63 acres beyond, sweeping through 400 streets and lanes, and consuming 13,200 houses, 89 churches and 52 livery company halls.

Amazingly, records report than fewer than 20 people lost their lives – a figure that former Watford Observer reporter turned author Cate Cain doesn’t buy, and which gave her the idea for her children’s book, The Jade Boy, published this month by Templar.

“I’ve always suspected that wasn’t very likely,“ says the former Watford resident who now lives in St Albans.

“It got me thinking – what would be a good reason to destroy old London in a fire?

“I’m a real conspiracy theorist, and I’ve got no historical backing for this whatsoever, but I’ve got a theory.

“The cities in Europe were becoming terribly grand, you had all these massive building schemes going on in Paris and Rome, whereas London was insanitary, the streets were an open drain, the year before, 1665, there had been a terrible plague.

“I just wondered whether some people in London had the idea of sweeping all of this away and having a lovely new city – and a really good side effect would be getting rid of all the disease-ridden slums.“

And so the germ of The Jade Boy was planted.

“And then I took it to another level by adding magic and ancient Egyptian mummies and things,“ Cate laughs.

Eleven-year-old Jem works in the household of a powerful but corrupt duke, who is visited by the sinister Count Cazalon. The count is planning something terrible and Jem appears to be central to his wicked scheme. It is up to Jem and his friends to stop the devastation.

“I wanted to write the sort of classic children’s books that I read when I was nine, ten, 11,“ says Cate. “Susan Cooper’s The Dark is Rising series, and Alan Garner’s stories, those kind of books where it’s the real world, but tinged with horror, just on the edge of your eye-line.“

And Cate has written just that.

She entered the book, the first one she had written and which took her just five months to complete, in to the Times Chicken House Children’s Fiction Competition in 2011 and made it to first the long-list, then the short-list and then the final five.

“I didn’t win but afterwards I got a call from the director of Chicken House Publishing, Barry Cunningham – the man who discovered JK Rowling,“ says Cate. “He gave me lots of tips on writing for children and said that, although there wasn’t room on their list for it, I must send it off to other publishing companies because he thought it would find a home.“

Cate took on board all of Barry’s suggestions and sent it out to lots of houses and, last September, heard that Templar was going to publish the book – the same week her adult novel, Kitty Peck and the Music Hall Murders, won a publishing contract with Faber & Faber in a competition run by Stylist magazine.

“It was quite amazing – and a little bit odd,“ she laughs. “It’s been quite a year.“

  • The Jade Boy by Cate Cain is out now from Templar publishing. Details: templarco.co.uk