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
Historiography of the fall of the Western Roman Empire launched by the Eastern Emperor Justinian in the 6th century, and meant to reunite the Empire, that eventually caused the most damage to Italy, as well as straining the Eastern Empire militarily. Following these wars, Rome and other Italian cities would fall into severe decline (Rome itself was almost completely abandoned). Another blow came with the Persian invasion of the East in the 7th century, immediately followed by the Muslim conquests, especially of Egypt, which curtailed much of the key trade in the Mediterranean on which Europe depended. The Empire was to live on in the East for many centuries,