Gratian, AV solidus, Trier. 

DN GRATIANVS PF AVG, helmeted, pearl diademed, draped, 
cuirassed bust left, holding spear and shield, three stars
on helmet.
VOTA PVBLICA, Gratian and Valens, nimbate and wearing
imperial robes, seated facing, each holding mappa and sceptre,
the emperor on the left raising his mappa.

Mintmark TR dot OB. 
RIC IX Trier 18e. 

With permission of Numismatik Leu, auction 83.