EDINBURGH CASTLE will be transformed into Hogwarts School of Witchcraft and Wizardry as part of a £50,000 launch party for the eagerly anticipated new Harry Potter book.

The transformation has been overseen by JK Rowling, the author of the series, and will be the centrepiece of one of the most expensive and extravagant launch parties in the history of publishing.

The magical atmosphere of the famous novels about the teenage wizard will be re- created for the 70 children picked from thousands of hopefuls to attend the launch of Harry Potter and the Half-Blood Prince next weekend.

It is one of thousands of events around the world to mark the publication of what is expected to be the fastest selling book in history. It is anticipated that more than 2m copies will be sold in the UK, and 10m worldwide, within 24 hours of its publication.

The biggest party, Spellbound 2005, will be at Mount Prospect, Illinois, where more than 10,000 Potter fans will take part in a series of activities, including Wizard Chess — with real people acting as the pieces — land-based quidditch, costume contests and riding a virtual-reality broom flight simulator.

Bookshops around the UK are planning launch parties and events, with a record number of stores arranging to open their doors at midnight on Friday. The Ottakar’s book chain will change its name to Pottakar’s for one week to celebrate the publication.

However, the main event is a personal reading from the writer herself. On Friday evening the young guests and their parents or guardians will be collected from a reception at the City Chambers in Edinburgh by 12 carriages drawn by black horses adorned with black ostrich plumes and driven by coachmen dressed in capes.

The castle will be dramatically illuminated and fire- eaters, torch throwers and jugglers will line the cobbled streets as the children proceed up Royal Mile.

Prefects with lanterns will lead the way to the castle’s Queen Anne building, which will be transformed to resemble the school entrance hall.

Rowling plans to make her appearance at 12.01am from behind a secret panel to read the first chapter of the new book, a copy of which will be given to each child.

The following evening, the children will be “sorted” into one of the four Hogwarts houses — Gryffindor, Hufflepuff, Ravenclaw and Slytherin. The guests will then be assigned to a house table, lined with benches, before wizard-themed food is served on gold platters.

The banquet will take place in the castle’s Jacobite Room, which has been hired at a cost of more than £500 an hour and will be decorated with school banners and illuminated with torches. The food for the Hogwarts-style banquet has been devised by Digby Trout, Edinburgh Castle’s caterers, whose basic menu starts at £39 a head.

As well as creating tuck shop favourites such as pumpkin pasties, chocolate frogs and Bertie Bott’s Every Flavour Beans, the caterers have also developed their own recipe for butter beer. The non-alcoholic mulled cider is first drunk by Harry in the third book in the series and is described by Rowling as tasting “a little bit like less sickly butterscotch”.

The platters will be piled high with meats, including chicken, chops and sausages, all the trimmings, desserts and mint humbugs in a feast reminiscent of the first meal that Harry eats on his arrival at the school.

Other Harry Potter treats will be put in goodie bags for the children to take away, along with mementos of their weekend.

The finale will be a children’s press conference on Sunday, which will be closed to adult reporters. “It’s going to be a magical experience for the children,” said Lucy Holden, spokeswoman for Bloomsbury, publisher of the Harry Potter series.

“As they first arrive, the castle will be illuminated and there will be all sorts of sounds and sights to greet the children, with entertainment laid on.

“JK Rowling has been very much involved — she always wants events to be focused on the children. She has been consulted at every stage.”

Helena van der Ploeg, general manager of Digby Trout restaurants, said the staff had great fun dreaming up the Hogwarts menu.

“Everything we serve will be along a Hogwarts theme — we’ve even had to create a few new recipes,” she said. “Everyone here has used it as an excuse to reread all the books.”

Catherine Lockerbie, director of the Edinburgh International Book Festival, said: “This year’s launch will be the best Harry Potter launch yet, not just because it’s in such a spectacular setting, but because it brings Jo Rowling into close contact with children.”

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