Diadumenian (/daɪˌædʊˈmiːniən/dy-AD-uu-MEE-nee-ən;Latin:Marcus Opellius Antoninus Diadumenianus; 14September 208 – June 218) was the son of theRoman emperorMacrinus and served as his co-ruler for a brief time in 218. His mother, Macrinus' wife, is calledNonia Celsa in the unreliableHistoria Augusta, though this name may have been fictional. Diadumenian becamecaesar in May 217, shortly after his father's accession to the imperial throne.Elagabalus, a relative of the recently deceasedCaracalla, revolted in May of the following year, and Diadumenian was elevated to co-emperor. After Macrinus was defeated in theBattle of Antioch on 8 June 218, Diadumenian was sent to the court ofArtabanus IV of Parthia to ensure his safety; however, he was captured and executed along the way. After his death and that of his father, theSenate declared both of them enemies of Rome and had their names struck from records and their images destroyed — a process known in modern scholarship asdamnatio memoriae.
Diadumenian was born on 14 September 208,[2] named Marcus Opellius Diadumenianus, toMacrinus, thepraetorian prefect and future emperor ofBerber origin.[3] The unreliableHistoria Augusta, a collection ofbiographies of Roman emperors and usurpers, mistakenly names Diadumenian as "Diadumenus".[4] The same source also states that Diadumenian's mother (Macrinus' wife) was calledNonia Celsa, though this name may have been invented by the author of the text.[5] Little information survives about Diadumenian, although the details of his physical appearance can be deduced from coinage and a description from theHistoria Augusta, which relates that he was "beautiful beyond all others, somewhat tall of stature, with golden hair, black eyes and an aquiline nose; his chin was wholly lovely in its molding, his mouth designed for a kiss, and he was by nature strong and by training graceful".[6]
Having served as praetorian prefect underCaracalla, Macrinus participated in a plot to have the Emperor assassinated and exploited the resulting power vacuum to seize the throne for himself on 11 April 217, three days after Caracalla's death.[7] Shortly after, the eight-year-old Diadumenian was elevated tocaesar – formalising his position as heir to the throne – atZeugma, while his guard was escorting him fromAntioch toMesopotamia to join his father. He was also given the name Antoninus, in honour of theAntonine dynasty, at this time.[6][8] On 16 May 218 a revolt against him and his father was launched inEmesa byElagabalus, whose mother,Julia Soaemias, was Caracalla's cousin. In order to put down the revolt, Macrinus led his legions to a fort atApamea. There Macrinus elevated Diadumenian toaugustus, making him co-emperor. After Macrinus was defeated by Elagabalus on 8 June 218, at theBattle of Antioch, Macrinus fled north and then to theBosporus. Before fleeing, he entrusted Diadumenian to loyal servants, instructing them to take him into theParthian Empire, to the court ofArtabanus IV, to ensure his safety. Diadumenian was captured en route in Zeugma and executed in late June.[9][10] His head was brought to Elagabalus and reportedly kept as a trophy.[11]
Following the demise of both Macrinus and Diadumenian, theRoman Senate quickly proclaimed their support for Elagabalus, declaring the former emperors to be enemies of the state. They were subject to a process known in modern scholarship asdamnatio memoriae, with their images and mentions in inscriptions andpapyri being destroyed during the reign of Elagabalus.[12] In an attempt to wipe out all traces of Diadumenian and his father, Elagabalus dated his own reign to the end of that of Caracalla.[4] Surviving busts of Diadumenian are mangled, with the facial features barely being discernible.[13]
Aureus of Macrinus, which features Diadumenian on the reverse, seated on a platform alongside his father, with the allegory ofLiberalitas before them.[14]
Aureus of Diadumenian. The reverse depicts him asprinceps iuventutis (official heir) between military standards.[15]
A very rare denarius of Diadumenian asaugustus, minted in the last weeks of his life, between late April and early June 218.[16]
Whilecaesar, a large number of coins were struck for Diadumenian, although fewer than the amount struck for his father. Coins in which he is depicted asaugustus are extremely limited, and the only known coins from this time aredenarii. This has led to the suggestion, first proposed by the ancientnumismatistCurtis Clay, that a large issue of coins was being made for Diadumenian; however, they were quickly melted down when the news of Macrinus' defeat spread. Someeastern provincial coins from the period exist which give Diadumenian the titlesebastos, at the time the Greek equivalent of the Romanaugustus.[9] In terms of gold coins, Diadumenian has one known style ofaureus, bearing his image on theobverse and displayingSpes standing on thereverse, and one known style of half-aureus, bearing his image on the obverse and displaying himself holding asceptre andstandard.[17]
Friedberg, Arthur L.; Friedberg, Ira S.; Friedberg, Robert (2017).Gold Coins of the World - 9th edition: From Ancient Times to the Present. An Illustrated Standard Catlaog with Valuations. Coin & Currency Institute.ISBN978-0-87184-009-7.
