IMP C P GALLIENVS P F AVG, radiate bust right // PIETAS AVGG, Valerian and Gallienus standing face to face, sacrificing at altar; one holds eaqle-tipped sceptre, the other a parazonium. 20mm, 3.25 grams. Samosata mint. RSC 792; RIC 447. 

Gallienus (253–268 CE) was Roman emperor during the Crisis of the Third Century, ruling first jointly with his father Valerian I and, after Valerian's capture by the Persians in 260, as sole emperor. His reign was marked by invasions, rebellions and the fragmentation of the Empire, including the emergence of the Gallic Empire in the west and the growing independence of Palmyra in the east. Despite these difficulties, Gallienus introduced important military reforms and successfully defended the central Roman territories against numerous challengers. He was assassinated in 268 while besieging the rebel general Aureolus at Mediolanum (Milan) and was succeeded by Claudius II Gothicus.