Other authors noted at the event included novelist Ian McEwan, who won the Galaxy Book of the Year award for his tragedy On Chesil Beach as well as the award for Reader's Digest Author of the Year.
Gordon Brown said of Ms Rowling's accomplishments: "She has joined a distinguished line of British authors whose work has got the whole country reading, and whose books will be read for many years to come by successive generations."
Ms Rowling said of the honour: "I haven't been pensioned off just yet with a Lifetime Achievement Award", which was given to thriller write John Grisham last year.
The WH Smith Children's Book of the Year, meanwhile, was Horrid Henry and the Abominable Snowman.
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