|MARCVS OPELLIVS DIADVMENIANVS
was appointed Caesar at the age of 9 when his father Macrinus obtained
the purple through a coup against Caracalla in 217 A.D. To associate
his son with the imperial legacy of the Antonine and Severan dynasty,
Macrinus gave him the added name of ANTONINVS. Diadumenian was
raised by his father to the rank of Co-Augustus around May, 218.
After a brief reign of 14 months Macrinus was overthrown and killed by in June 218 by forces loyal to Julia Maesa and Elagabalus. The young Co-Augustus attempted to flee to Parthia, but was captured and executed.
(Contributed by Jan de Veen)
Denarius (19x20mm, 3.38gr), Struck 218 A.D. in Rome
Obv: M OPEL ANT DIADVMENIAN CAES Bare-headed, draped bust right
Rev: PRINC IVVENTVTIS Diadumenian standing left, baton in right hand, scepter in left, two standards at right.
RIC 107, RSC 12, Sear 7448 var., BMC 82 note.
Bob Rinaldi Collection