He served as the vicarius orientis in 325 before being appointed the eastern praetorian prefect, probably in late 326, when the emperor Constantine I returned from Italy.
This was an unusual appointment, as the office of praetorian prefect was reserved for members of the Equestrian order, not senators, and it displayed the emperor's confidence in Valerius Maximus, allowing him to exercise command over the extensive resources of the East.
Valerius Maximus served him there until late 333 or early 334, when Constantius returned to his father's court at Constantinople.
They possibly had one son together, as his second nomen and cognomen suggest, named Lucius Valerius Septimius Bassus.
It has been postulated that they had two children, a son, Maximus, and a daughter, Valeria, who may have become a Christian through her possible marriage, as the nomina and cognomen of one of their children supports, to Rufius Maecius Placidus, consularis vir in 370, son of Postumius Rufius Festus Avienus and wife Maecia Placida.