Scotland's most important collection of antique coins has been stolen, police have revealed.
The collection featured coins dating back 900 years
The unique collection, which has been valued at more than £500,000, features pieces dating back to 1136, when the very first Scottish coins were minted.
A total of more than 1,000 coins were stolen from the home of Lord and Lady Stewartby in Broughton, near Peebles.
A "substantial reward" has been offered to anyone who can help recover the collection.
The raid happened more than a month ago, but police have only just released details of the theft for operational reasons.
Coin dealers have also been asked to look out for the stolen collection.
Lord Stewartby has been collecting coins since he was a child, and is recognised as being a leading authority on the subject.
His collection contained a number of irreplaceable pieces, many of which were unique, including one coin that was struck in Aberdeen 900 years ago.
Most of the coins are thought to have been minted in Scotland between 1136 and the reign of Alexander III in the late 13th Century.
Other specimens were created under David II in the 14th century, and James I and James II in the 1400s.
Lord Stewartby made his collection available for experts in numismatics - the study of coins - to carry out research, and had been working on compiling a full catalogue.
His daughter, Lydia Pretzlik, said the family had been "devastated" by the theft, which happened when the house was lying empty. A quantity of jewellery was also taken.
Mrs Pretzlik added: "My father collected the first of those coins when he was a young boy, so in many ways it represents the loss of his life's work.
"He is much more concerned with retaining the integrity of the collection, which is the best collection of Scottish coins in the world, than with any commercial loss."
Mrs Pretzlik said it was impossible to say for sure whether the coins had been specifically targeted by the thieves.
But she added: "The collection is pretty well known and it is an unusual thing to steal unless you know what you are looking for."
Nick Holmes, senior curator in numismatics at the National Museums of Scotland, said the theft had dealt a devastating blow to the study of historic coins in Scotland.
He added: "In terms of that period, Lord Stewartby had more coins in his collection than the National Museums of Scotland have.
"He had managed to collect a number of very rare pieces which were previously unknown.
"It wouldn't be putting it mildly to say that this theft has put the study of numismatics back 50 years because if the collection is not recovered all of the work Lord Stewartby has put in over the past half century will be lost."
Mr Holmes said it would be "very difficult" for the thieves to sell the rarest coins in Britain because dealers would realise they were from the stolen collection.
But he added: "The problem comes with the more common pieces which are not as easily identifiable as being from this collection, or if the thieves manage to take it abroad."
A Lothian and Borders Police spokesman added: "This collection is a unique part of Scottish history and its loss cannot be underestimated. We have carried out a significant amount of inquiry so far and are now appealing to the public for help.
"We would appeal to anyone who may have information as to the whereabouts of the collection or anyone who has been offered some rare and unique coins."