Diadumenian was the son and co-ruler of Roman Emperor Macrinus. His mother was Nonia Celsa, whose name may be fictitious. Diadumenian became Caesar in May 217. Elagabalus revolted in May 218, and Diadumenian was elevated to co-emperor. After Macrinus was defeated in the Battle of Antioch, on 8 June 218, Diadumenian was sent to the court of Artabanus V to ensure his safety; however, he was captured and executed along the way, in late June.
A large number of coins were struck for Diadumenian, although less than the amount struck for his father. Coins in which he is depicted as Augustus are extremely limited, and the only known coins from this time are denarii.
Notably, some eastern provincial coins from the period exist which give Diadumenian the title Sebastes, at the time the Greek equivalent of the Roman augustus. In terms of gold coins, Diadumenian has one known style of aureus, bearing his image on the obverse, and displaying Spes standing on the reverse, and one known style of half-aureus, bearing his image on the obverse, and displaying himself holding a scepter and standard.
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