The book contains seven handwritten passages of Gaelic text, written in the margins.
These describe – among other things – how a monastery was founded by St Columba and St Drostan at Deer, near Mintlaw.
It has never been established exactly how big the building was, how long it survived or how many monks lived there.
Archaeologists from Glasgow University were yesterday drafted in by the friends of the Book of Deer group to try to trace any remains of the building.
Their meticulous search, which has so far failed to yield any clues, is taking place inside the old church at Old Deer and in the church graveyard.