Historiography of the fall of the Western Roman Empire Historiography of the fall of the Western Roman Empire The causes and mechanisms of the Fall of the Western Roman Empire are a historical theme that was introduced by historian Edward Gibbon in his 1776 book "The History of 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 and well-referenced account.
Historiography of the fall of the Western Roman Empire the Huns as deeply significant in the fall of the Western Empire long before they themselves became a military threat to the Empire. He postulates that the Hunnic expansion caused unprecedented immigration in 376 and 406 by barbarian groupings who had become significantly more politically and militarily capable than in previous eras. This impacted an empire already at maximum stretch due to the Sassanid pressure. Essentially he argues that the external pressures of 376–470 could have brought the Western Empire down at any point in its history. He disputes Gibbon's contention that Christianity and moral decay led to the decline.