One of the most important reasons for the fall of Rome was the economy. There were many economic problems in Rome. I"ll first start with the prisoners of war or the lack there of. When Emperor Hadrian drew the boundaries and said Rome could grow no more in 121 AD, the empire lost one of the three largest sources of income, prisoners of war. Another major source of income was trade. Rome acted like the middleman in trade between the provinces. The provinces were told what to produce, and they produced it, sold it to Rome, who would then sell it to the other provinces for a higher price. But when the provinces became more and more independent, they cut out the middleman all together. So in that action the provinces were taking one of Rome's largest sources of income. The third economic source for Rome was taxes. As the two other sources of income began to disappear, the Rome government raised the taxes for the people of Rome. The taxes skyrocketed and the plebeians, Rome's everyday average poor people who made up almost all of Rome, started to revolt.
The next reason for the decline of Rome was that the people neighboring Rome like Germany and Persia grew increasingly hostile toward the Romans. They despised them for their earlier patriotism and for the fact that while Rome was growing, they kept taking their land. These neighbors became more sophisticated as they grew out of barbarism. Soon these people became Rome's enemies.
Another reason for Rome's decline was the decay of the upper class or the patricians. I don't know for sure what happed to them. It was probably numerous things including lead poising from the lead pipes, inbreeding, and them only looking for there own pleasure and not the good of the empire. They were the leaders of the country and with them only caring about themselves and not looking toward making Rome a better place they played a large role in the decline of Rome.
