LONDON (REUTERS) - An exhibition celebrating the 20th anniversary of the first Harry Potter book's publication is offering fans a chance to view rare memorabilia.

The highlights in Harry Potter: A History Of Magic, held in the British Library in London, include author J.K. Rowling's first annotated sketch of Hogwarts school as well as her handwritten list of its teachers and subjects.

The exhibition also features historic artefacts from the library's collection.

These include alchemists' scrolls from the 1500s and Chinese oracle bones from the 12th century.

The seven Harry Potter books have been translated into 68 languages and have sold more than 400 million copies worldwide.

The final book was published in 2007, with the series spawning blockbuster films, an American theme park and a hit stage play.

Rowling herself appears to have enjoyed the blend of her fictional world with the library's collection.

"Encountering objects for real that have in some shape or form figured in my books has been quite wonderful," the 52-year-old said in a statement.

The exhibition runs from Friday until Feb 28.