As Severus Alexander - medallion-type reverse
SEVERUS ALEXANDER. AE As. Rome, 231 AD.
Obv. IMP SEV ALEXANDER AVG laureated bust right with draped left shoulder
Rev. FIDES MILITVM SC Jupiter standing r., holding thunderbolt and scepter; facing him, Alexander holding scepter and sacrificing over altar, crowned by Mars, shield at feet; behind, 2 standards.
RIC 556b (R); Cohen 62 (15 F)
Special and rare issue for 231 AD, along with silver, bronze sestertii, large and small medallions featuring Alexander and Mamaea.
Ths issue celebrates the military capacities of the yound emperor and the fidelity of the army before departure for Persia to counter the advances of the first Sassanid king Ardashir I in the Roman province of Mesopotamia.
Paris coin fair, ex J. Creusy, 23 Oct 1999
CGB Rome IV fixed priced catalog, lot 139 (see https://web.archive.org/web/20120204110204/http://www.cgb.fr/monnaies/rome/r04/r040018.html ).