In the year 330 Constantine founded a new imperial city in the east, which became known as Constantinople. Accompanying Diocletian's system of tetrarchy, the creation of this new city affirmed the separation of the Roman Empire into the east and the west. The Eastern Roman Empire held a series of advantages over the west both socially and economically. The Western Roman Empire was the weaker empire and a bad leadership and government along with attacks from barbarians led to the demise of the Western Roman Empire.
However the Roman Empire was severely weakened by the fourth century and the government was less capable of withstanding the barbarian attacks.
There are many reasons for the collapse of the Western Roman Empire in the fifth century. A major reason was the political corruption and the instabilities of the government. The last ruling emperor of a united Roman Empire was Theodosius I. At his death in 395, he divided the empire leaving the east to his son Arcadius and the west to his other son Honorius. Constantinople and the Eastern Roman empire remained strong while the Western Roman Empire deteriorated in the face of economic depression and weak emperors.
The rule of good emperors came to an end when Commodus became emperor in AD180. His murder in AD 192 was followed by a civil war by rivals to the throne. A series of rulers under what was known as `The Severan Dynasty' ensued. Lucian Septimius Severus who became emperor in AD 193 severely weakened the imperial defenses when he disbanded the Praetorian Guard and replaced them with his own troops. While Rome remained a large empire there was a complete lack of constitution. After Septimus Severus all power derived from the army, which led to corruption in a quest for power. Between 235 and 284 there was a series of insane emperors who were frequently assassinated.
Farmers who could not afford to pay the high taxes of the government fled their land. Barbarians occupied this abandoned land. Anarchy and the decaying of trade routes resulted in the decline of commerce. There was a devaluation of the...