In the 4th century the Pons Cestius was rebuilt by the Emperors Valentinian I, Valens and Gratian and re-dedicated in 370 as the Pons Gratiani.
In the 4th century, Valentinian spent much of his reign defending the Rhine frontier against a mixed horde of Sarmatians, Goths, and Quadi under their king Gabinius, who was slain at the treaty table by the Roman Marcellinus, son of the praefect of Gaul, Maximinus.
Coins of Tetricus I and also Valentinian I (indicating the milecastle to be one of only 10 yielding 4th century material)