An oil painting of an old man that has been newly authenticated as a work by Rembrandt is to go on public display at Woburn Abbey in Bedfordshire this week.
The painting - known as The Old Rabbi - was last exhibited in 1950 and has hung ever since in a private room.
Last year Ernst van de Wetering, a leading expert on the 17th Century artist, was invited to study the work.
He said it was "an outstanding specimen of Rembrandt's art" that impressively depicted "dignity in old age".
"This is a discovery and a fine addition to the abbey's wonderful collection of Dutch art," said general manager Jonathan Irby.
"We are very excited about bringing this exquisite painting into the public eye, especially since visitors will be able to get within a few inches of it."
It is believed that the Woburn picture and a painting in the Gemaldegalerie in Berlin, thought to be a portrait of Rembrandt's wife Saskia, were intended as a pair.
Both were painted in 1643 on a mahogany panel taken from the same sugar case and share similarities of design and biblical style.