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.
Campaign history of the Roman military war with Yazdegerd II was again swiftly concluded by treaty after both parties battled threats elsewhere. Many theories have been advanced in way of explanation for decline of the Roman Empire, and many dates given for its fall, from the onset of its decline in the 3rd century to the fall of Constantinople in 1453. Militarily, however, the Empire finally fell after first being overrun by various non-Roman peoples and then having its heart in Italy seized by Germanic troops in a revolt. The historicity and exact dates are uncertain, and some historians do not consider that the Empire fell