Thieves broke into a stately home and stole a rare Chippendale table valued at more than £100,000.
The 1775 Chippendale table was made especially for Newby Hall
The suspects broke in through a shuttered and locked window at Newby Hall, near Ripon, in the early hours of Friday.
The George III rosewood table was made especially for the hall in 1775 and is said to be of worldwide importance.
Police urged anyone with information about the theft, or any witnesses, to contact them.
Newby Hall owner Richard Compton said the table was well-known after being featured in many papers and books on furniture and would be impossible to sell on the open market.
He said: "This is a devastating blow for all of us and a terrible loss.
"I do hope we are able to bring it back to Newby to restore the integrity of the Chippendale collection for the benefit of British furniture history and future visitors to Newby."