Record price for rare illustrated Harry Potter book

Rowling's personal annotations cover 43 pages

A rare first edition of Harry Potter and the Philosopher's Stone, with annotations and drawings by author JK Rowling, has sold for a record price.

After a bidding war between two buyers the book sold for £150,000, a new record for a printed book by Rowling.

It was part of a sale of annotated first edition books by 50 UK and Commonwealth writers.

The sale raised a total of £439,200 for English PEN, which campaigns for freedom of expression.

"The sale room fell silent as two determined bidders vied for the prized edition," said a spokesperson for Sotheby's in London.

"Bidding leapt in increments of up to £25,000 and the hammer finally fell, to a round of applause, on a £150,000 telephone bid."

A sleeping baby Harry on the Dursleys' doorstep is one of 22 original illustrations by JK Rowling

The second-highest price of the auction was achieved by a copy of Matilda by Roald Dahl, with new illustrations by Quentin Blake, which sold for £30,000.

The sale was attended by a number of authors whose works were featured in the sale, including Helen Fielding, Colm Toibin, Jeanette Winterson, Frederick Forsyth, Ben Okri, Margaret Drabble, Andrea Levy and Wendy Cope.

Dr Philip W Errington of Sotheby's called the books "the ultimate first editions" due to the "remarkable personal insights that the authors have granted us, through their annotations".

Genesis of Quidditch

Rowling's personal annotations cover 43 pages and include references to the Harry Potter series as a whole and also the film adaptations.

Her notes include a reflection on an anomaly in chapter four about snapped wands and a section of text she refused to cut.

Rowling also talks about the genesis of the game of Quidditch.

Quidditch, she writes "was invented in a small hotel in Manchester after a row with my then boyfriend.

"I had been pondering the things that hold a society together, cause it to congregate and signify its particular character and knew I needed a sport."

The broomstick-based pursuit, she continues, "infuriates men… which is quite satisfying given my state of mind when I invented it."

Rowling's 22 original illustrations include drawings of an Albus Dumbledore chocolate frog card, a brooding Snape, Norbert the Norwegian Ridgeback dragon and a man with two faces.

The largest amount paid for a JK Rowling book was the £2 million fetched in 2007 by a handwritten copy of Tales of Beedle the Bard.

Rowling wrote and illustrated seven copies of the collection of fairy tales, but only auctioned one to raise funds for her Children's Voice charity.