Decline of The Roman Empire - Highlights

Highlights

The decline of the Roman Empire was a process spanning many centuries; there is no consensus when it might have begun but many dates and time lines have been proposed by historians.

3rd century

• The Crisis of the Third Century (234 - 284), a period of political instability.
• The reign of Emperor Diocletian (284 - 305), who attempted substantial political and economic reforms, many of which would remain in force in the following centuries.

4th century

• The reign of Constantine I (306 - 337), who built the new eastern capital of Constantinople and converted to Christianity, legalizing and even favoring to some extent this religion. All Roman emperors after Constantine, except for Julian, would be Christians.
• The first war with the Visigoths (376 - 382), culminating in the Battle of Adrianople (August 9, 378), in which a large Roman army was defeated by the Visigoths, and Emperor Valens was killed. The Visigoths, fleeing a migration of the Huns, had been allowed to settle within the borders of the Empire by Valens, but were mistreated by the local Roman administrators, and rebelled.
• The reign of Theodosius I (379 - 395), last emperor to reunite under his authority the western and eastern halves of the Empire. Theodosius continued and intensified the policies against paganism of his predecessors, eventually outlawing it, and making Nicaean Christianity the state religion.

5th century

• The Crossing of the Rhine: on December 31, 406 (or 405, according to some historians), a mixed band of Vandals, Suebi and Alans crossed the frozen river Rhine at Moguntiacum (modern Mainz), and began to ravage Gaul. Some moved on to the regions of Hispania and Africa. The Empire would never regain control over most of these lands.
• The second war with the Visigoths, led by king Alaric, in which they raided Greece, and then invaded Italy, culminating in the sack of Rome (410). The Visigoths eventually left Italy and founded the Visigothic Kingdom in southern Gaul and Hispania.
• The rise of the Hunnic Empire under Attila and Bleda (434-453), who raided the Balkans, Gaul, and Italy, threatening both Constantinople and Rome.
• The second sack of Rome, this time by the Vandals (455).
• Failed counterstrikes against the Vandals (461 - 468). The Western Emperor Majorian planned a naval campaign against the Vandals to reconquer northern Africa in 461, but word of the preparations got out to the Vandals, who took the Roman fleet by surprise and destroyed it. A second naval expedition against the Vandals, sent by Emperors Leo I and Anthemius, was defeated in 468.

• Deposition of the last Western Emperors, Julius Nepos and Romulus Augustus (475 - 480). Julius Nepos, who had been nominated by the Eastern Emperor Zeno, was deposed by the rebelled magister militum Orestes, who installed his own son Romulus in the imperial throne. Both Zeno and his rival Basiliscus, in the East, continued to regard Julius Nepos, who fled to Dalmatia, as the legitimate Western Emperor, and Romulus as an usurper. Shortly after, Odoacer, magister militum appointed by Julius, invaded Italy, defeated Orestes, and deposed Romulus Augustus on September 4, 476. Odoacer then proclaimed himself ruler of Italy and asked the Eastern Emperor Zeno to become formal Emperor of both empires, and in so doing legalize Odoacer's own position as Imperial viceroy of Italy. Zeno did so, setting aside the claims of Nepos, who was murdered by his own soldiers in 480.
• Foundation of the Ostrogothic Kingdom in Italy (493). Concerned with the success and popularity of Odoacer, Zeno started a campaign against him, at first with words, then by inciting the Ostrogoths to take back Italy from him. They did as much, but then founded an independent kingdom of their own, under the rule of king Theodoric. Italy and the entire West were lost to the Empire.