Nicaea was one of the most prolific civic minting authorities in Bithynia, striking bronze throughout the third century under nearly every emperor who would accept the flattery. Joint-reign issues pairing Valerian with his son Gallienus are common to several Bithynian cities, produced in the window between Valerian's accession in 253 and his catastrophic capture by Shapur I at the Battle of Edessa in 260 — the only time a reigning Roman emperor was taken prisoner by a foreign enemy. After that humiliation, Gallienus ruled alone and the joint issues ceased.
Nicaea was one of the most prolific civic minting authorities in Bithynia, striking bronze throughout the third century under nearly every emperor who would accept the flattery. Joint-reign issues pairing Valerian with his son Gallienus are common to several Bithynian cities, produced in the window between Valerian's accession in 253 and his catastrophic capture by Shapur I at the Battle of Edessa in 260 — the only time a reigning Roman emperor was taken prisoner by a foreign enemy. After that humiliation, Gallienus ruled alone and the joint issues ceased.