The west, in large part, destroyed itself from within. Political rivalries for power, corrupt politicians and mismanagement of state funds weakened the west, to the point it that it did not have enough unity to defend against the Germans. We also have to consider another topic that's been discussed in this forum regarding multiculturalism. The non-Roman population in western Rome adopted some of the concepts surrounding the culture, but there were divisions within the empire which made it difficult unite everyone in a common cause.
The barbarian invasions of the Western Roman Empire from the 4th century on didn't help either. It is kind of hard to maintain cohesion when you get overrun every 50 years or so and some of the barbarians stick around. What is remarkable about the west is how many Roman institutions stuck around if only in an altered form.
Most important to say is that, the movement of germanic tribes headed forward in western direction. So Its obvious that a economical weak westroman empire, which had LOTS of HUGE inner political problems, rebellions and corruption going on, did not survive the constant movement and attempts of the germanic tribes to obtain some land.Also look at the border of the westroman empire. It goes through huge parts of europe, while the west roman empire, in fact, didnt have that much land in europe itself to defend. They could focus on their defence in their european counties, which were in fact easier to defend, due to their economical strenght, military reforms, political and culutural unity (christianity as single main religion). Its just the difference. TO SUM UP: WEST ROMAN EMPIRE: VERY HUGE BORDERS TO DEFEND, WITH A WEAK ECONOMY, MILITARY, AND A WEAK SOCIETY BASED ON FARMING ETC. (IN GENERAL: CIVIl WAR LIKE REBELLIONS, AND CONFLICTS BETWEEN PAGANS AND CHRISTIANS; AND CORRUPTION )EASt ROMAN EMPIRE: VERY SMALL BORDER TO DEFEND, WHILE THEY WERE MORE WEALTHY WITH A STRONG ECONOMY BASED ON TRADEMENT, WHICH WAS NEVER AFFECTED BY WAR, LIKE FARmING. THEIR CULUTRAL UNITY CAUSED BY THEIR SINGLE RELIGION GAVE THEM MORE "POWER"
It is my understanding that the plague only caused between a 10-15% population loss and that among the old and infirm. I thought the plague did not affect the young and generally healthy as bad as other groups not strictly necessary militarily.
I said the death rate was upwards of 25% In what follows the Roman death-rate is estimated at 33-50%.What ever the actual rate, it was a significant--if not primary--cause for the fall of the Roman Empire in the West.
Between 166 and 266 AD the Roman Empire was hit by two separate plagues, each one nearly as deadly as the more famous Black Death of the Middle Ages.The first one, known as the Antonine Plague lasted eighteen years and killed millions of people all over the empire. It may have even killed the famous Marcus Aurelius, the philosopher and soldier, last of the Good Emperors.The second Plague broke out in 251 AD and raged for fifteen years right in the middle of the dreadful 3rd Century Crisis which it may well have started or at least deepened.It is believed that the two diseases were Smallpox and Measles, both virulent killers though which order they came in is not known.This carnage may have unbalanced Classical Civilization: physically by removing taxpayers, workers and recruits necessary to maintain the Roman Social Order and it's army at their accustomed level; and psychologically by showing the helplessness of its rulers and religions in the face of catastrophe. This might well have caused millions of bereaved survivors to turn away from Paganism to Christianity and similar other-worldly religions and philosophies.Their effects lasted for centuries and the population of the Mediterranean World fell for about 800 years before recovery began.By killing more Romans than Barbarians and Civil Wars combined, by an order of magnitude, these catastrophes may have been the trigger for the fall of Rome and the eclipse of Classical Civilization.Given what we know of the ravages of Smallpox on the Indian inhabitants of the Americas after 1492, where death rates are estimated at 80-90% of effected populations, this seems all too likely; although it seems the Roman death-rate was more in the vicinity of 33-50%.No culture, especially one with such a low level of technology--it is not widely appreciated how primitive Classical technology was, even in comparison to the Middle Ages--could hope to survive a disaster of this magnitude.The clincher was an outbreak of Bubonic Plague, the Plague of Justinian starting 541 AD, which ravaged the Mediterranean World about half a century after the Fall of Rome. This paved the way for the Rise of Islam and by dividing the Mediterranean World permanently between two hostile religions, ensured that nothing like the Roman Empire could never exist again.Read more: http://wiki.answers.com/Q/What_kind_of_plagues_have_been_in_the_Roman_Empire#ixzz1jUimpTAn
Truth be told, though, Donnie, the Byzantines weren’t successful in defending those vast boundaries. When push came to shove, they were only able to defend a fraction of that, and likely because the prize jewel of Constantinople was such a defensively-minded city. Yes, it was more than the western Romans could defend, but the Byzantines weren’t unstoppable during the early Middle Ages, either.