Diadumenian (Caesar, AD 217-218). Moesia, Inferior, Nicopolis ad Istrum. Æ (28mm, 11.7g). Marcus Claudius Agrippa, consular legate. Bareheaded, draped, and cuirassed bust r. R/ River-god Istrus reclining left, resting hand on galley and holding reeds. H&J, Markianopolis 8.25.32.3; Varbanov 3645 corr. (obv. and rev. legends).