is mentioned as the praefectus vigilum at the accession of Galba, A. D. 68, who deprived him of this office. He was probably restored to his office by Otho, when the latter ob tained the supreme power, A. D. 69, for we find him serving as tribune in Otho's army in the cam. paign against Caecina, the general of Vitellius. His brother, Julius Gratus, was praefect of the camp in Caecina's army, and Galba's soldiers, suspecting that Julius Fronto meditated treachery, put him in chains. His brother Gratus met with the same treatment from Caecina's soldiers, and for the same reason. (Tac. Hist. 1.20, 2.26.)