The most agreed upon date for the Fall of the Rome is 476, when the Germanic general Odavacar overthrew the last remaining Roman Emperor. Some say that the split of the eastern and western part of the Roman Empire ruled by different emperors caused Rome to collapse. Some argued that the collapse started when inflation hit the Romans severely after Marcus Aurelius' reign. Regardless, many factors led to the Fall of Rome.
Many factors weakened Rome for its fall. These included: Christianity, lead, monetary trouble, decadence, and military troubles. Problems within Rome and pressures from outside of Rome helped facilitate its fall.
Imperial incompetence was a major factor. Since there was no clear-cut method for choosing emperor's this left a lot to interpretation. The emperor, the senate, and the Praetorian Guard had a large say. Over 100 years, there were 37 emperors, many killing the last to take his spot, and some selling the position. Therefore, no strong consistent leaders helped unify Rome.
Diseases killed many of the poor who lived in unsanitized squalor. Lead pipes used for water also killed many of the rich.
All of these reasons contributed to the fall of the greatest empire man has ever seen.
