Macrinus named his son Diadumenian co-Augustus within a year after his own accession but both perished at the hands of their soldiers soon afterwards.
AR Denarius Caesar, 217--218 A.D.
2.6 g., 17 mm. Augustus, 218 A.D.
Obv. M OPEL ANT DIADVMENIAN CAES: Draped and bare-headed bust right
Rev. PRINC IVVENTVTIS: Diadumenian standing left, holding baton adn scepter, two standards behind him
Van Meter 4/1