Valens

Valens was the younger brother of Valentinian who made him co-emperor soon after his own accession. He then sent Valens off to take care of the eastern portion of the empire. Making Constantinopolis his capital, he dealt with the Persian factor as best he could which wasn't all that great and saw his borders shrink as a consequence. His ineptitude showed most compellingly at the battle of Adrianopolis in 378. Resettled barbarians had been allowed within the nominal borders of the empire but were allowed to keep their arms. As the barbarians became squeezed from the double whammy of external tribes pushing against their lands and the systematic and extra-official hard-line policies of lower Roman government officials they became aggressive once more and aimed to push southward.

Near the city of Adrianopolis they gathered with the intention of making war and Valens prepared to meet them in battle. He sent for reinforcements from Gratian but before these could arrive he figured in a bout of short-sighted arrogance that he could go at it alone and claim the glory all to himself afterward. On an exceedingly poorly executed attack plan the Romans attacked the barbarians. In what apparently was meant to be a surprise attack, he rushed the barbarians before getting his soldiers into formation and before they had eaten. It was also a very hot and dusty day making their attack that much more energy-sapping. The barbarians watched as their counterparts fumbled and figured out their strategy. Their general sent his cavalry in an outflanking maneuver and managed to encircle Valens's infantry and subsequently slaughtered most. Valens himself perished in battle and the loss of the army along with the demoralizing effect to the rest of the military was another step in the inexorable fall of the empire almost one hundred years later.

AU Solidus

RIC 2b (Nicomedia), Depeyrot 10/2 Solidus Obv: DNVALENSPFAVG - Diademed, draped and cuirassed bust right.
Rev: RESTITVTORREIPVBLICAE Exe: SMN - Valens standing, facing, holding labarum and Victory on globe. $600 5/22/02.

AU Scripulum

RIC 26.2, Depeyrot 43/3 Heavy Scripulum Obv: DNVALENSPFAVG - Diademed (pearls), draped and cuirassed bust right.
Rev: VICTORIAAVGVSTORVM Exe: /ANOB - Victory seated right, holding shield reading VOT/X/MVL/XX. 373-375 (Antioch).

AR Miliarense

RIC 1a (IX, Constantinopolis) Miliarense Obv: DNVALENSPFAVG - Diademed (pearls), draped and cuirassed bust right.
Rev: GLORIAROMANORVM Exe: CONSΔ - Valens and Valentinian I standing facing under arch, each holding a scepter and globe. c.364-367 (Rome).

AR Argenteus

RIC 11c (Constantinopolis) Argenteus Obv: DNVALENSPFAVG - Diademed, draped and cuirassed bust right.
Rev: No legend Exe: CONSP - Wreath, VOT/V within. 364-367 (Constantinopolis).

AR Siliqua

RIC 6e(var.) Siliqua Obv: DNVALENSPFAVG - Diademed (pearls), draped and cuirassed bust right.
Rev: RESTITVTORREIP Exe: LV - Valens standing facing, holding labarum and Victory on globe. [RIC unlisted mint mark].

AE1

RIC 1b (IX, Heraclea) AE1 Obv: DNVALENSPFAVG - Diademed (pearls), draped and cuirassed bust right.
Rev: RESTITVTORREIPVBLICAE Exe: SMH - Valens standing, facing, holding labarum and Victory on globe. 364-367 (Heraclea).

AE3

RIC 3b (Heraclea), C 11 AE3 Obv: DNVALENSPFAVG - Diademed, draped and cuirassed bust right.
Rev: GLORIAROMANORVM Exe: SMH - Valens advancing right, dragging captive and holding labarum.