The History of the Decline and Fall of the Roman Empire is a six-volume work by the English historian Edward Gibbon. It traces Western civilization (as well as the Islamic and Mongolian conquests) from the height of the Roman Empire to the fall of Byzantium in the fifteenth century. Volume I was published in 1776 and went through six printings. Volumes II and III were published in 1781; volumes IV, V, and VI in 1788–1789. The six volumes cover the history, from 98 to 1590, of the Roman Empire, the history of early Christianity and then of the Roman State Church, and the history of Europe, and discusses the decline of the Roman Empire among other things. Thesis Gibbon offers an explanation for the fall of the Roman Empire, a task made difficult by a lack of comprehensive written sources, though he was not the only historian to attempt it. According to Gibbon, the Roman Empire succumbed to barbarian invasions in large part due to the gradual loss of civic virtue among its citizens. He began an ongoing controversy about the role of Christianity, but he gave great weight to other causes of internal decline and to attacks from outside the Empire. Like other Enlightenment thinkers and British citizens of the age steeped in institutional anti-Catholicism, Gibbon held in contempt the Middle Ages as a priest-ridden, superstitious Dark Age. It was not until his own era, the "Age of Reason", with its emphasis on rational thought, it was believed, that human history could resume its progress. Style Gibbon's tone was detached, dispassionate, and yet critical. He can lapse into moralisation and aphorism: Criticism Numerous tracts were published criticising his work. In response, Gibbon defended his work with the 1779 publication of A Vindication ... of the Decline and Fall of the Roman Empire. Edward Gibbon's central thesis in his explanation of how the Roman Empire fell, that it was due to embracing Christianity, is not widely accepted by scholars today. Gibbon argued that with the empire's new Christian character, large sums of wealth that would have otherwise been used in the secular affairs in promoting the state were transferred to promoting the activities of the Church. However, the pre-Christian empire also spent large financial sums on religious affairs and it is unclear whether or not the change of religion increased the amount of resources the empire spent on religion. Gibbon