Elizabeth Digeser (Making of a Christian Empire) observes that the Roman emperor Diocletian came to the purple with a disadvantage: He was a usurper. He needed to secure his power, lest another usurp his place. His strategy was to distribute power to a Tetrarchy, and to claim divine right for his rule.
He started right away with the latter process, emphasizing the approval of the gods in the accession: “Diocletian’s mints claimed that he was under Jupiter’s care (Juppiter conservator Augusti). Other issues declared Jupiter and Hercules to be the divine companions of the Augusti and the Caesars. . . . In 287 Diocletian heightened this sense of divine right when he began to use the family name Jovius and Maximian [one of the other emperors in the Tetrarchy] the name Herculius, epithets that literally meant ‘son of Jupiter’ and ‘son of Hercules.’ Augustus and many others had claimed descent from deified human forebears, but no one had ever claimed divine parentage in quite this way before.” Orators said that he saw a “manifest God” (praesentum . . . deum) when he looked at Maximian (28).
It worked, and it didn’t. Diocletian stayed in power, and was able to retire to his villa to grow cabbages. But he was nearly the last pagan Roman emperor. He overreached, and the kingdom was taken from him. Sounds almost biblical when you put it that way.