The coin may be evidence of early trade links
A silver coin dug up as part of a hoard is the oldest piece of Roman money found in Britain, experts believe.
The coin, which has been dated to 211BC, was found near Hallaton in Leicestershire with 5,000 other coins, a helmet and decorated bowl.
Uncovered by archaeologists in 2000, the coin's significance has just been recognised, the county council said.
It said the coin, which has the Goddess Roma on one side, was "something very special".
The other side depicts mythical twins Castor and Pollux sat on galloping horses.
Iron Age shrine
David Sprason, Leicestershire County Council cabinet member for communities and wellbeing, said: "Leicestershire boasts the largest number of Iron Age coins ever professionally excavated in Britain in the Hallaton Treasure.
"To also have the oldest Roman coin ever found is something very special."
The Hallaton coin is on display at Harborough Museum, Market Harborough, alongside other coins that were excavated at a late Iron Age shrine of the Corieltavi tribe dating to the first century AD.
Museum staff said it was a mystery as to how this coin came into the possession of the local Corieltavi tribe.
Some archaeologists have however speculated that such Roman Republican coins found their way into Britain before the Roman conquest in AD 43 and were evidence of exchange through trade or diplomacy.
Professor David Mattingly of the University of Leicester's School of Archaeology and Ancient History said: "This hoard has changed our view of just how significant the East Midlands were in this period and this coin is a good example.
"It indicates there was contact between this region and the Roman Empire despite the distance between the East Midlands and the parts of Britain the Romans arrived in, like Colchester and Chichester."
He added: "It was minted in Rome at the time of the Hannibalic wars and here it is turning up after what must have been quite a long journey."