This coin was recently found by Roger Paul. It’s a penny of Edward I, of which detectorists have unearthed many thousands as singleton finds. However, at this time of year any hammered silver coin would be a welcome find.
The detail isn’t altogether clear but it is most likely to belong to class 4a or 4b. The legend on the reverse, CIVI TAS CAN TOR, points towards the coin being struck at the mint situated in Canterbury.
Roger’s coin is weak in places but still good enough to grade Fine so to a collector it should be worth £18 – £20.