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
Fall of the Western Roman Empire Nepos in 480. Gibbon gave a classic formulation of reasons why the Fall happened. He began an ongoing controversy by attributing a significant role to Christianity in the Western Roman Empire's fall, which is no longer accepted by modern Roman historians. However, he did give great weight to other causes of internal decline as well and to the attacks from outside the Empire. Alexander Demandt enumerated 210 different theories on why Rome fell, and new ideas have emerged since. Historians still try to analyze the reasons for loss of political control over a vast territory (and, as a subsidiary theme,