Computer shop owner Robert Abbot, 53, carpenter Dave Allen, 59, and herd manager Mick Rae, 63, had been sleeping in the field two days after lockdown lifted in September 2020.
Robert, from Essex, said: ‘After finishing breakfast I turned on my machine — a Minelab Equinox 800 — and having walked around six paces from the tent, found several tent pegs and, just under the surface, a late Roman silver siliqua in pristine condition.
‘A few moments later I found another one beside it.’
Mick, from Wiltshire and Dave, also of Essex, joined in to help uncover 161 silver siliqua and miliarense from AD 340-402.
The collection is expected to fetch up to £40,000 when it is auctioned on May 17 by specialist Noonans.
‘Ironically, we’d been camping there two weeks previously for a week-long detecting outing,’ Robert said.
‘What we hadn’t realised is we’d actually camped right on top of the area where the coins were found.’
