The causes and mechanisms of the decline of the Roman Empire are a historical theme that was introduced by historian Edward Gibbon in his 1776 book The Decline and Fall of the Roman Empire. He started an ongoing historiographical discussion about what caused the Fall of the Western Roman Empire, and the reduced power of the remaining Eastern Empire, in the 4th–5th centuries. Gibbon was not the first to speculate on why the Empire collapsed, but he was the first to give a well-researched[POV? – discuss] and well-referenced[POV? – discuss] account. Many theories of causality have been explored. In 1984, Alexander Demandt enumerated 210 different theories on why Rome fell, and new theories emerged thereafter.[1][2] Gibbon himself explored ideas of internal decline (the disintegration of political, economic, military, and other social institutions, civil wars) and of attacks from outside the Empire. "From the eighteenth century onward," historian Glen Bowersock wrote, "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."[3]
There is no consensus on a date for the start of the Decline. Gibbon started his account in 98.[citation needed] The year 376 is taken as pivotal by many modern historians.[citation needed] In that year there was an unmanageable influx of Goths and other barbarians into the Balkan provinces, and the situation of the Western Empire generally worsened thereafter, with recoveries being incomplete and temporary. Significant events include 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, and the second sack of Rome in 455, with the death of Majorian in 461 marking the end of the last opportunity for recovery.
Gibbon took September 4, 476 as a convenient marker for the final dissolution of the Western Roman Empire, when Romulus Augustus, the last Emperor of the Western Roman Empire, was deposed by Odoacer, a Germanic chieftain.[citation needed] Some modern historians question the significance of the year 476 for its end.[4] Julius Nepos, the Western emperor recognized by the Eastern Roman Empire, continued to rule in Dalmatia, until he was assassinated in 480. The Ostrogothic rulers of Italia considered themselves upholders of the direct line of Roman tradition, and the Eastern emperors considered themselves the sole rightful Roman rulers of a united empire.[citation needed] Roman cultural traditions continued throughout the territory of the Western Empire, and a recent school of interpretation argues that the great political changes can more accurately be described as a complex cultural transformation, rather than a fall