REGALIANVS, one of the usurpers in the reign of Gallienus. Trebellius and Victor call him Regillianus, "and from this name (says Eckhel), Goltzius, on his own authority, has fabricated Q. Nonnius Regillianus. But there are genuine coins which call him P. C. Regalianus. He was a Dacian by birth and was believed to be a lineal descendent of Decebalus, whom Trajan with difficulty subdued. Regalianus is said to have possessed the heroic courage and great qualities of that king. He served under Valerian and commanded the Illyrian army when Ingenuns assumed the title of Augustus, about the end of the year 260.
The cruelties inflicted by Gallienus on the troops and inhabitants in Moesia, who had declared in favour of Ingenuus, induced them, after the defeat of that usurper, to elect Regalianus, who had already distinguished himself by his victories over the Sarmatians, against whom, even after his election, he continued to signalise his valour and augment his military renown. Some say that he was defeated and slain in battle by Gallienus; others that he was killed by his own soldiers, in concert with the people of Illyria, who dreaded becoming victims again to the inhuman vengeance of Gallienus.- Beauvais calculates his death to have occured about the end of August, A.D. 263, and Eckhel, on the authority of Trebellius, assigns the same date to the event. Instead, however, of agreeing with Beauvais that the medals of Regalianus are to be found only in the collection of Goltzius, Eckhel publishes two coins from the Cabinet of Vienna with the style IMP. C. P. C. REGALIANVS, and his head radiated; the legends of the reverses being respectively LIBERALITAS AVGGG. and ORIENS AVG. The great German numismatist also ascribes another coin to Regalianus, which is preserved in that Imperial collection.- The coins of Regalianus are in small brass or billion, and of extreme rarity.