Septimius Severus, AE medallion of Pergamon, Mysia. 33.93 g. 

AVT KAICA CEPTIMIW CEBHRW PERTINA K, laureate, draped, cuirassed bust 
right, two countermarks: head of Caracalla right (Howgego 70) and
wreath (Howgego 480).
EPI CTRA IOUL POLLIWNOC B NEOKORWN PERGAMHNWN, Athena standing
left, holding a twig of a serpent-entwined olive branch to her 
left; shield behind her. 

SNG BN 2189.

Courtesy of Helios Auction 5, June 2011