Catherine Cookson has lost her title as Britain's most borrowed author after a 17-year reign as queen of the libraries.
She lost her throne to the children's writer Jacqueline Wilson in a coup said to prove that libraries are reaching new generations of readers.
However, the creator of Harry Potter, J K Rowling, managed to reach only number 42 in the library lending chart published by Public Lending Right.
Cookson, who died six years ago aged 91, published more than 100 books and sold more than 90 million copies in a lifetime of writing. The enduring appeal of her stories of 19th-century working-class life in northern England gave her the title of most borrowed author every year since the records started.
Yet in 2003 she was supplanted by Wilson, 58, who has been writing children's books for 20 years after training as a journalist and working on the teenage girl's magazine Jackie.
Cookson was pushed into fourth place by Wilson, second-placed Danielle Steel and the romantic fiction writer Josephine Cox, who came third.
"This is the first time since our records began that we have had a new author replacing Catherine Cookson at number one," said Dr Jim Parker, Public Lending Right's registrar.
"Having an eminent children's author such as Jacqueline Wilson at number one surely reflects the passion of young readers and the vibrancy of the public library service for an emerging generation."
Wilson, who has sold more than 12 million copies of her books in Britain alone, said she was "surprised and totally delighted" at the news.
"Every author is thrilled to know their books are selling but I know I share with many authors an almost greater thrill when your books are borrowed from libraries.
"My thanks go to the public library service and to librarians everywhere who work so hard to help ensure that everyone has the opportunity to enjoy books and reading," she said.
Wilson, who also had the most borrowed book in London with Sleepovers, recorded a total of more than two million loans last year.
Her books, such as The Illustrated Mum and The Story of Tracey Beaker, have been praised for portraying realistic children coping with convincing everyday dilemmas. The Illustrated Mum was shortlisted for the 1999 Whitbread Children's Book and won the 1999 Children's Book of the Year at the British Book Awards. Tracey Beaker and another book, Double Act, have been filmed for television.
Wilson also dominated the chart of the most borrowed children's books, taking 16 of the 20 places.
Harry Potter filled the remaining four places, and J K Rowling had some consolation for her lowly place in the author's list as Harry Potter and the Chamber of Secrets was the most borrowed children's book of 2003. Harry Potter and the Prison of Azkaban was second.
Most borrowed book of the year was The Summons by John Grisham, while the top non-fiction title was Dave Pelzer's The Lost Boy.