It was scarcely possible that the eyes of contemporaries should discover in the public felicity the latent causes of decay and corruption. This long peace, and the uniform government of the Romans, introduced a slow and secret poison into the vitals of the empire. The minds of men were gradually reduced to the same level, the fire of genius was extinguished, and even the military spirit evaporated. The natives of Europe were brave and robust. Spain, Gaul, Britain, and Illyricum, supplied the legions with excellent soldiers, and constituted the real strength of the monarchy. Their personal valour remained, but they no longer possessed that public courage which is nourished by the love of independence, the sense of national honour, the presence of danger, and the habit of command. They received laws and governors from the will of their sovereign, and trusted for their defence to a mercenary army. The posterity of their boldest leaders was contented with the rank of citizens and subjects. The most aspiring spirits resorted to the court or standard of the emperors; and the deserted provinces, deprived of political strength or union, insensibly sunk into the languid indifference of private life.
Edward Gibbon (April 27, 1737 (O.S.) (May 8, 1737 (N.S.)) - January 16, 1794) was arguably the most influential historian since the time of Tacitus. His magnum opus, The History of the Decline and Fall of the Roman Empire, published between 1776 and 1788, is a groundbreaking work whose influence endures to this day.