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
History of the Roman Empire was brought to an end by the reign of Commodus from 180 to 192. Commodus was the son of Marcus Aurelius, making him the first direct successor in a century, breaking the scheme of adoptive successors that had worked so well. He was co-emperor with his father from 177. When he became sole emperor upon the death of his father in 180, it was at first seen as a hopeful sign by the people of the Roman Empire. Nevertheless, as generous and magnanimous as his father was, Commodus was just the opposite. In "The Decline and Fall of the Roman