Countermark

https://rpc.ashmus.ox.ac.uk/countermark/1231 
GIC 557 corr
ΠΡΧ
rectangular 
9.5 x 6 mm 
Uncertain mint of Bithynia (Bithynia)
might have been applied at Prusa or Prusias; was possibly to give a civic validation to the coins of Nero in AD 68/9? 
List of countermarks View on a map

Coins with this countermark

Number Image TypeNumber CoinNumber VolumeNumber
RPC I, 2103 Show 2103 1 1
RPC I, 2104 Show 2104 1 1
RPC I, 2104 Show 2104 2 1
RPC I, 2104 Show 2104 3 1