Caracalla AE29 of Serdica, Thrace. 

AVT K M AVRH CEVH ANTWNEINOC, laureate head right.
OVLPIAC CERDIKHC, Ares standing facing, naked and helmeted,
head right, holding shield and spear in left hand, right
hand raised.

Varbanov 2182 (this coin); Ruzicka 195; Sofia 3229.