Winston Churchill once said there are two reasons for anything happening; the popularly accepted reason and the real reason(s). So here are the REAL reasons behind the Decline And Fall of the Roman Empire (as outlined by Edward Gibbon, Arnold Toynbee and other eminent historians of the classical period) Imperial "Overstretch" : The Roman Empire at its height covered most of southern, central and western Europe (Gaul, Hispania, Italia, Britannia, parts of Germania, etc.), Asia Minor and North Africa. Centuries before the European Union, the Romans had succeeded in unifying most of Europe under the Pax Romana and instituted one currency (the Sessertii ) long before the Euro. A full three-fourths of humanity lived and died under the long reign of the Caesars. All the far-flung provinces of empire were linked by the famed Roman roads ("All roads lead to Rome ") and sea-going galleys in the Mediterranean sea and Atlantic ocean . Roman maritime expeditions fr