Tacitus, AE antoninianus. Serdica. 

IMP CM CL TACITVS PF AVG, radiate, draped, cuirassed bust right.
PROVIDEN DEOR, Providentia standing right, holding two
standards, facing Sol, standing left, holding globe and
raising right hand. 
Mintmark KA Delta. 

RIC V-1 195 var (obv. legend)