It's Gratian with a GLORIA ROMANORVM reverse (Emperor dragging captive) and though hard to make out, looks like it is from Siscia.
And Victor comes through again! I've rotated the OP photos and cropped them down: I have one similar to yours, not terribly well-preserved, I'm afraid: Gratian, AD 367-383. Roman Æ centenionalis, 1.75 g, 17.3 mm, 7h. Siscia, AD 372-375. Obv: D N GRATIANVS P F AVG, pearl-diademed, draped and cuirassed bust, right. Rev: GLORIA RO-MANORVM, emperor advancing right, dragging captive by the hair with right hand and holding labarum in left; complex combination of mint marks: Refs: RIC ix, p. 147, 14c xxxvii; RCV 20065; Cohen 23.