The grandson of Valentinian II, Valentinian III was the son of Constantius III (who in turn had no relation to the Constantines). He grew up like royalty and became Caesar, then emperor very early in life. However, he had no real power as first his mother and then the general Aetius restricted his ability to rule by imposing their own will. Apparently in an effort to rid himself of the influence of Aetius he managed to get the general assassinated but rather than free him, Aetius's bodyguard avenged his murder by killing the emperor a few months later.
RIC 2010 Solidus Obv: DNPLAVALENTINIANVSPFAVG, His diademed, draped and cuirassed bust right
Rev: VICTORIAAVGGG, Valentinian, his right foot on serpent with human head, standing facing holding long cross and victory on globe. Lot sold for $439 11/8/01.
RIC 2073 Tremissis Obv: DNPLAVALENTINIANVSPFAVG, rosette-diademed, draped and cuirassed bust right
Rev: No legend Exe: COMOB; Cross within wreath.
RIC 2085, Cohen 11 Half Siliqua Obv: DNPLAVALENTINIANVSPF; Diademed, draped and cuirassed bust right.
Rev: VICTORIAAVGG; Victory standing left, holding wreath and palm. Lot sold for $360 11/13/01.
RIC 2122, LRBC 843 AE4 Obv: DNVALENTINIANVSPFAVG; Diademed, draped bust right.
Rev: VICTORIAAVG; Victory advancing left, * in left field.