His famous stories such as James and the Giant Peach, BFG and Matilda remain among the most popular with youngsters. Now their power is being harnessed as part of a campaign called Sheffield City Read.

It was launched at an event attended by almost 1,000 schoolchildren at Sheffield University's Octagon Centre, organised with the Roald Dahl Foundation to celebrate what would have been the author's 92nd birthday.

Youngsters asked questions, ranging from his books to whether he got fat on his favourite food, chocolate. The young fan was assured his hero always remained tall and slim.

Then a surprise was in store as Dahl's second wife Felicity took to the stage to round off proceedings.

Addressing the crowd, who had come from 31 schools, she said: "What a fantastic group of wonderful children, I think you are amazing.

"I'm delighted to be here. There have been a series of events around the country but this has been the biggest – Sheffield's stolen the show."

Over the next few weeks, hundreds of copies of an updated version of Roald Dahl's autobiography Boy, containing extra photographs, school reports and details of his life, will be given out free from city libraries.

The book will be read in groups at Sheffield Children's Library on Thursdays September 18 and 25 and October 9, where poet Matt Black will also be talking about the author and reading his poetry.

Sessions are at 9.30am to 10.30am, 11am to noon and 1.30pm to 2.30pm.

Felicity said Roald he would approve of the Sheffield campaign.

"It was his crusade to make every child in the world literate. While some find reading very difficult, because of the style in which his books are written and because of the way he gets inside the mind of a child, they cannot put them down," she said.

Amanda Conquy of the Roald Dahl Foundation said Sheffield had been chosen for this year's main Roald Dahl Day event, partly because he supported the children's hospital.

The author funded a paediatric haemotology unit and his foundation is paying for a specialist nurse.

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