A rare 500-year-old letter signed by Richard III is expected to fetch up to £82,500 when it is auctioned in Los Angeles next week.
The document dates back to the 1470s when Richard was still Duke of Gloucester and shows the future king intervening in a land dispute between the 2nd Earl of Westmorland and his tenants.
It will be auctioned by Los Angeles firm Nate D. Sanders on Tuesday and is expected to sell for between $75,000 and $125,000 (£49,500 and £82,500). Laura Yntema, from the US auctioneers, said: "The piece has been very popular, probably because of the new interest in Richard III and also because of its incredibly rarity. "We've had several bids from the United Kingdom, but I'm not sure if I should say what cities. "We've also had interest from all over the world, but no bids from outside the UK or US yet. "The auction is still early though. The signature is lovely - quite large and thankfully not deteriorated. It's an impressive document in person. "Where ever King Richard's remains wind up, it would be a nice addition for visitors to see I think."
The letter is among a number of Richard III-related historical items which have recently come to light following the discovery of the monarch's body in Leicester, in August. Last December, a gold coin bearing Richard's personal emblem (a boar's head) sold for three times its estimate at auction in London. A private collector paid £36,000 for the item, which was discovered at Claybrooke Magna, about 12 miles from Bosworth Battlefield in August 2012. Dickon Dearman, owner of Churchgate Auctions, in Scudamore Road, Leicester, said: "There's certainly been more interest following the discovery, but you'd expect that.
"When something like this comes into the public eye, people tend to get related items revalued and you find more items are put up for auction.
"It also has an effect on price – values tend to go up if things become more widely known."
Last Sunday, a rare coin bearing the face of Richard III was sold for £1,400.
The silver groat, a four pence piece in its day, went under the hammer at Suffolk auctioneers Lockdales. Experts estimated it would sell for between £1,000 and £1,500.
Auctioneer James Sadler, of Lockdales, in Ipswich, said: "This coin is so very rare in the market and, of course, it's so topical. In 20 years of auctioneering, I've never seen one before.
"It's been put into the auction by a private collector who has decided this might be the right time to sell, following the discovery of the body."
Colleague Chris Elmy said: "The estimate of the coin was £1,000 to £1,500 so it was within that range. The buyer was a collector of English medieval coins.
"The bidding was between this collector in the room and an anonymous bidder on the internet.
"This particular coin is likely to be added to future books about Richard III's coinage as it is an unpublished combination of designs."
The coin would have been made at the Tower of London Mint between 1484 to 1485 – but is very rare, as Richard reigned for just over two years.
It has Latin inscriptions on both sides. The first reads Ricard di Gra Rex Angl's Franc (Richard by the grace of God, King of England and France).
The other side reads Posui Deum Adiutore Meum (I have made God my helper) and Civitas London (City of London).