The decline of the Roman Empire refers to the gradual societal collapse of the Western Roman Empire. Many theories of causality prevail, but most concern the disintegration of political, economic, military, and other social institutions, in tandem with foreign invasions and usurpers from within the empire. The English historian Edward Gibbon, author of The Decline and Fall of the Roman Empire (1776) made this concept part of the framework of the English language, but he was not the first to speculate on why and when the Empire collapsed. “From the eighteenth century onward,” Glen W. Bowersock has remarked, “we have been obsessed with the fall: it has been valued as an archetype for every perceived decline, and, hence, as a symbol for our own fears.” It remains one of the greatest historical questions, and has a tradition rich in scholarly interest. In 1984, German professor Alexander Demandt published a collection of 210 theories on why Rome fell, and new theories have emerged since then.
This slow decline occurred over a period of four centuries, culminating on September 4, 476, when Romulus Augustus, the last Emperor of the Western Roman Empire, was deposed by Odoacer, a Germanic chieftain. Some modern historians question the significance of this date, and not simply because Julius Nepos, the legitimate emperor recognized by the East Roman Empire, continued to live in Salona, Dalmatia, until he was assassinated in 480. The Ostrogoths who succeeded considered themselves upholders of the direct line of Roman traditions. The Eastern Roman Empire was going from strength to strength and continued until the Fall of Constantinople on May 29, 1453.
Many events throughout the empire’s history are considered to have worsened the empire’s so-called “decline”. The Battle of Adrianople in 378, the death of Theodosius I in 395 (the last time the Roman Empire was politically unified), the crossing of the Rhine in 406 by Germanic tribes, the execution of Stilicho in 408, the sack of Rome in 410, the death of Constantius III in 421, the death of Aetius in 454, the second sack of Rome in 455, and the death of Majorian in 461 are all macrohistorical events concerning the decline of the Western Roman Empire.