A Roman cavalry helmet bought for £2.2m at auction after it was discovered in a Cumbrian field is to go on public display for the first time.
The Crosby Garrett Helmet, named after the village near where it was found, is to feature as part of a Royal Academy show called Bronze.
A private collector outbid a Carlisle museum at the auction in 2010.
Bronze co-curator David Ekserdjian said the helmet, which is almost 2,000 years old, was a "masterpiece".
He said: "Even if this helmet had been known about for as long as anybody can remember, we'd still want it in the show because it's a fantastic work of art.