Cognomen of Diocletian
Cognomen of Diocletian, Tetrarchy.
 Praetorian prefect of emperor Honorius 
Praetorian prefect under emperor Honorius . In 407, he was made Praefectus Praetorio Illyrici by Stilicho, in order to wrest this prefecture from the eastern empire, but remained dependent on the Gothic king Alaricus  (Sozom. Hist. eccl. 8,25,3; 9,4,3; Zos. 5,48,2). In 409, he became Praef. Praet. …