History of the Roman Empire disputes about the supreme authority, this finally formalised a peaceful succession of the emperor: in each half a "Caesar" would rise up to replace the "Augustus" and select a new "Caesar". On May 1, 305, Diocletian and Maximian abdicated in favour of their "Caesars". Galerius named the two new "Caesars": his nephew Maximinus for himself, and Flavius Valerius Severus for Constantius. The arrangement worked well under Diocletian and Maximian and shortly thereafter. The internal tensions within the Roman government were less acute than they had been. In "The Decline and Fall of the Roman Empire", Edward Gibbon notes that this
The History of the Decline and Fall of the Roman Empire to barbarian invasions in large part due to the gradual loss of civic virtue among its citizens. He began an ongoing controversy about the role of Christianity, but he gave great weight to other causes of internal decline and to attacks from outside the Empire. Like other Enlightenment thinkers and British citizens of the age steeped in institutional anti-Catholicism, Gibbon held in contempt the Middle Ages as a priest-ridden, superstitious Dark Age. It was not until his own era, the "Age of Reason", with its emphasis on rational thought, it was believed, that human history could resume its progress. Gibbon's