J.R.R Tolkien's annotated map of Middle-earth has been discovered inside a copy of The Lord of the Rings.
It reveals the author's observation that Hobbiton is on the same latitude as Oxford, and implies that the Italian city of Ravenna could have been the inspiration behind the fictional city of Minas Tirith.
The map was discovered by a specialist at Blackwell's Rare Books in a copy of the illustrator Pauline Baynes's copy of The Lord of the Rings.
She had removed the map from another edition of the novel as she began work on her own colour map of Middle-earth for Tolkien, which would go on to be published by Allen & Unwin in 1970.
Tolkien had then copiously annotated it in green ink and pencil, with Baynes adding her own notes to the document while she worked.
Blackwell's, which is exhibiting the map in Oxford and selling it for pounds 60,000, said it is "an important document, and perhaps the finest piece of Tolkien ephemera to emerge in the last 20 years at least". The bookshop said it demonstrates "the exacting nature" of Tolkien's creative vision. He corrects place names, provides extra ones, and gives Baynes a host of suggestions about the map's various flora and fauna.
Hobbiton, he notes, "is assumed to be approx at latitude of Oxford"; Tolkien was a professor of Anglo-Saxon at Oxford University.
The novelist also uses Belgrade, Cyprus, and Jerusalem as other reference points. According to Blackwell's, this suggests that "the city of Ravenna is the inspiration behind Minas Tirith - a key location in the third book of The Lord of The Rings trilogy."
"The map shows how completely obsessed he was with the details. Anyone else interfered at their peril," said Sian Wainwright at Blackwell's.
"He was tricky to work with, but very rewarding in the end."
Henry Gott, modern first editions specialist at Blackwell's Rare Books, said the map was "an exciting and important discovery" that "demonstrates the care exercised by both [Tolkien and Baynes] in their mapping of Tolkien's creative vision".