Valentinian I AE3, Siscia. AD 364-375. 16 mm, 2.54 g. 

D N VALENTINIANVS P F AVG, pearl diademed, draped and cuirassed bust right.
SECVRITAS REIPVBLICAE, Victory walking left, holding wreath and palm branch.
D in left field, S in right field. 

Mintmark Delta SISC. 

RIC IX Siscia 15a, type xiii.

With permission of Savoca Numismatik GmbH Blue Auction 6, Lot 1435, April 2018.