Many Roman Imperial coin collectors have a goal of acquiring one coin of each emperor. There are perhaps fewer than a dozen such "complete" collections in the world. One reason is the coins of this emperor. FORVM believes less than 25 coins of Regalianus are known to exist. Little is known of Cornelius Publius Gaius Regalianus. He appears to have been of Dacian origin and claimed descent from the Dacian king Decbalus, whose defeat by Trajan is depicted on Trajan's column. Literary sources locate his coup d'etat on the lower Danube, in Moesia, but his coins and those of his wife have been found only much further west, in Austria. All of his coins were over-struck on older coins. After a reign of only a couple months, Regalianus was murdered by his own troops after they were defeated by Gallienus.