There were many reasons for the fall of the Roman Empire. Each one interweaved with the other. Many even blame the initiation of Christianity in 337 AD by Constantine the Great as the definitive cause while others blame it on increases in unemployment, inflation, military expenditure and slave labour while others blame it on the ethical issues such the decline in morals, the lack of discipline of the armies and the political corruption within the Empire. Three major contributions that led to the collapse of the once great empire were: the heavy military spending in order to expand the Empire, the over-reliance on slave labour which led to an increase in unemployment, and the political corruption and abuse of power by the Praetorian Guard leading to the unfair selection of many disreputable emperors and the assassination of those not favoured by the Guard.

One of the main reasons of the collapse of the Roman Empire was the over expenditure on the military to constantly fund wars abroad. In order for the Romans to invade and conquer other provinces they had to spend heavily on their legions. The Roman armies and supply lines became over-stretched resulting in thousands of soldiers being recruited and deployed from Rome into other territories as invaders or defenders. They also depended on soldiers to defend the borders of the lands they had conquered from barbarian attacks which resulted in the increased manufacturing of weapons and more money being spent on soldiers. High military spending left the Romans with very limited resources for other essential government projects such as the building of more public houses and the development of roads and aqueducts as well as leading to inflation. The over-expenditure on the military led the citizens of Rome to refuse the policies and laws enforced by the government and riots were commonplace in Rome during its last century. Due to the Roman citizens growing distrust of the Empire less people volunteered to join their armies which forced the military to hire common criminals and non-Roman mercenaries. The government raised taxes to aid their military expenditure which added to the low morale of the Roman population with every citizen losing a third of their weekly wage. The money raised to spend taxes was wasted on soldiers who constantly had to be replaced until the Romans could no longer afford to send large garrisons of troops abroad leaving their own borders poorly defended and vulnerable to attacks. The non-Roman mercenaries were too proud to serve a weakening empire and they began to conquer parts of the Empire as the Romans were unable to afford to send detachments and reserves to reclaim these areas. The city of Rome was left very poorly defended due to the deployment of troops to other provinces within the Empire which were defeated and taken by the barbarians making it considerably easier for them to conquer Rome. In order to ensure their loyalty, the wages of the soldiers were doubled and they were often promised discharge payments such as land or money. The military also spent loads of money on the transport of food and grain to ensure their soldiers were fed, horses were also vital, the roads and bridges needed to be repaired constantly and weapons also needed to be manufactured. The Romans believed that luxury interfered with discipline and failed to see that the soldiers would begin to live a more lavish lifestyle with the money they were promised. When the Romans spent their gold and silver in order to expand they failed to conquer any lands that would replace their depleted mines.
Another main cause leading to the demise of the Roman Empire was the dependency of the use of slave workers. The number of slave workers increased dramatically during the first two centuries of the Roman Empire. Rome’s dependency on slave labour led not only to a decline in morals, values and ethics but also the stagnation of new machinery to produce goods more efficiently and productively. The Romans were never short of slaves and treated them very sadistically which caused the slaves to revolt leading to a string of conflicts called the Servile Wars, the most famous one being the charge led by the gladiator slave, Spartacus. Common farmers who had to pay their workers could not afford to produce their goods at low prices and slaver