A first edition of The Hobbit broke the world record for a copy of the 1937 novel, more than doubling the previous mark. What made this copy so special? It was signed by J.R.R. Tolkien himself and features a hand-written inscription by the author for one of his students.

The book sold for a surprising £137,000 (around $209,000) at Sotheby’s in London. According to The BBC, the auction house only expected it to sell for £50,000 to £70,000. It smashed the previous record for a The Hobbit first edition, which was set in 2008 by a copy that went for £50,000 (over $76,000).

Tolkien signed the book for Katherine Kilbride, one of his students at Leeds University during the 1920s. It was just one of a few copies that featured a hand-written inscription by Tolkien. The inscription was written in Old English and was a portion of his incomplete book The Lost Road, notes The Guardian.

Kilbride, who died in 1966, also wrote a letter thanking Tolkien for the gift. The letter is kat Oxford’s Bodleian library.

First published in 1937, The Hobbit was the first introduction to Middle Earth, the setting for Tolkien’s The Lord of the Rings trilogy. Although a relatively short book, it was adapted into a three-part film by Peter Jackson.