The Empire from the Third-Century
Crisis to Justinian
The major factor that brought about the weakening and eventual destruction of the Empire is the defect of Augustus' political arrangement. Augustus never created a system that involved political succession after the death of an Emperor. The inability to guarantee imperial succession to any person is conceivably dangerous and very risky. Meaning, that any person, provided they are supported by a certain group, can take the throne, even by force of arms. This is exactly what happened after the death of Severus Alexander in A.D. 235. The result of no imperial succession was complete chaos in prominent areas in the Empire of Rome. Over a period of thirty years in the third century, known as the third century crisis, twenty-two legitimate emperors ruled over Rome, in a time when centralized power was needed most. Different groups of individuals, specifically the army, supported different leaders and this led to many bloody battles and civil wars.
As a result, troops left key places on the boarder protecting the Empire in order to fight. This left the frontier weakened and vulnerable to enemies such as the Barbarians in the north and the Persians in the east, who eventually did penetrate deep into the empire. Inflation also plagued the Empire with the collapse of the Roman currency system. However most importantly, a very important social change was taking place. Christianity was becoming widespread and was beginning to find approval among the classes of the Empire. Such a transformation led to the changes of ideas and ethics within the Empire.
With the end of the third century nearing, the Roman Empire found peace again--momentarily--in Diocletian who ruled from A.D. 286-305. It was Diocletian's thorough and successful reforms that improved conditions and soothed the pandemonium within the...