A "unique" Anglo-Saxon coin found in a field in south Wiltshire is expected to fetch up to £200,000 at auction.

The Gold Penny, or Mancus of 30 Pence, was unearthed by a metal detectorist in a field near West Dean in March 2020.

Weighing 4.82g, it was struck between 802 and 839 during the reign of Ecgberht, King of the West Saxons.

Thought to be the only late Anglo-Saxon gold coin in private hands, it is expected to fetch between £150,000 and £200,000 at auction on 8 September.

Auctioneer Peter Preston-Morley, from London-based Dix Noonan Webb, said it was "very exciting" to see the coin.

"Gold coins of this monarch were completely unknown until this one was found," he said.

He said the coin was analysed in June 2021 and found to be made of "high-purity gold".

Struck at a West Saxon mint, possibly in Southampton or Winchester, the coin bears the King's title 'Ecgbeorht Rex' around a monogram of the word Saxon.

Mr Preston-Morley said only eight other known gold coins were struck in England between 630 and 1257, seven of which are now held at the British museum.

Extremely valuable coins'
It is believed orders for mancuses to be struck were only given on special occasions or religious events, and the coins were produced for ceremonial or high-status payments.

"Mancuses would have been extremely valuable coins," he said.

"A single gold mancus would have bought the equivalent of 360 loaves of wheat bread."

Mr Preston-Morley added it had not been possible to date the coin to a more specific period due to limited records from Ecgberht's reign .