The Gospels of Queen Theutberga is to auction at Christie's London on July 15.
Dating to the middle of the ninth century AD, the book is the oldest known Western copy of the gospels in private hands. It's valued at £1m-1.5m ($1.5m-2.3m).
It's believed to have originated from a Benedictine abbey near the German city of Metz. Queen Theutberga, thought to be the book's original owner, was the wife of Lothaire II - king of Lorraine.
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