Antoninus Pius (138-61), reverse thunderbolt on a thron.
The coins are all from the Llanvaches hoard, found in 2006 not far from Caerleon and now on display there. All are Roman silver denarii (singular: denarius), produced at Rome. The hoard comprised intotal 599 denarii, buried in a greyware pot around AD 160.
To view this item in 3D, click: http://labs.casgliad.sequence.co.uk/caerleon-coin-6.aspx