P. C. Regalianus (died 260/261), known in English as Regalian, was Roman usurper for a few months in 260 and/or 261, during the Crisis of the Third Century, a period of intense political instability in the Roman Empire. Regalian was acclaimed emperor by the troops along the Danube river, a region of the empire that frequently experienced barbarian raids, probably in the hope that he might be able to secure the frontier.
Accounts by surviving literary sources concerning Regalian are brief and few in number, and are mostly considered unreliable. The Historia Augusta relates that he was of Dacian descent, and a descendant of the Dacian king Decebalus, but this is mostly rejected in modern scholarship. Regalianus was married to Sulpicia Dryantilla, a woman from a prestigious senatorial family, which instead points to Regalian also being of high-ranking Roman descent. Regalian's acclamation as emperor was in the wake of a previous usurpation attempt by Ingenuus, also proclaimed by the Danube troops, that had been defeated by emperor Gallienus (r. 253–268). Unlike Ingenuus, and revolutionary for an imperial claimant, Regalian founded his own mint at Carnuntum, his seat of power. He minted coins of himself and his wife, though they were typically of poor quality.
