The coin shown is a silver denarius of Marcus Aurelius. Bare headed portrait, with curly hair and beard, facing right, with the legend M ANTONINUS AUG IMP II. The reverse shows Providence holding globe and cornucopiae, with the legend PROV D FOR TRP (XVII or XVIII possibly XVIIII) COS III. These titles date this coin to 163, assuming that the failure to mention ARMENIACUS eliminates the possibility of 164 AD.