Tacitus, AE antoninianus. Serdica. 

IMP CM CL TACITVS AVG, radiate, draped, cuirassed bust right.
CONSERVAT MILIT, emperor standing right, holding spear or
sceptre, receiving globe from Jupiter standing left.
A or H in lower centre.
Mintmark KA. 
RIC V (1) 193, Estiot 2388, La Venera 1725
(Reverse wrongly described in RIC, corrected in Estiot)

AAH ebay, 2008.