Valentinian I, AE3, Siscia.

DN VALENTINI-ANVS PF AVG, pearl diademed, draped, cuirassed bust right.
GLORIA RO-MANORVM, Emperor in military dress, advancing right, 
head left, holding labarum, dragging captive behind him. 
Left field: F
Right field: D over P. 
Mintmark: BSISC zigzag. 
RIC IX Siscia 14a, type xliv(a).

With permission of Nemesis Ancient Coins.