Rare manuscripts found in a Gloucestershire castle's vaults have been proven to be by one of the world's most famous classical composers.
A concert is planned at the castle in November
Six arias from the Vivaldi Opera - La Costanza Trionfante Degli-amori e de gl'odii, were discovered in the archive of Berkeley Castle.
The works date back to 1716. They were discovered within a bound volume of 18th century Italian operatic extracts.
They are believed to be the only known copies of the opera.
Although discovered a while ago, the castle's archivist, David Smith, had to wait for the decision of Vivaldi academics as to their origin.
Now they have been proved to be by the great composer there will be a premier performance of the pieces at the castle later in November.