Constantius II, AE3 of Siscia.

DN CONSTAN-TIVS PF AVG, pearl-diademed, draped, cuirassed bust right.
FEL TEMP-REPARATIO, soldier spearing fallen horseman who 
is wearing a Phrygian helmet, reaching backwards,
M in left field.
Mintmark BSIS zigzag.

RIC VIII Siscia 369.

Dane's collection, July 2014.