Historiography of the fall of the Western Roman Empire Roman civilisation which under-girded the Empire. According to this school, drawing its basic premise from the Pirenne thesis, the Roman world underwent a gradual (though often violent) series of transformations, morphing into the medieval world. The historians belonging to this school often prefer to speak of Late Antiquity instead of the Fall of the Roman Empire. In "The History of the Decline and Fall of the Roman Empire" (1776–88), Edward Gibbon famously placed the blame on a loss of civic virtue among the Roman citizens. They gradually entrusted the role of defending the Empire to barbarian mercenaries who eventually turned
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