There were several reasons for the fall of the Roman Empire. One of the principle reasons was the split of the Empire into two parts which began with Diocletian. The true answer to the question is still up for debate but I am a historian and the down and dirty answer is this: The Roman government got complaisant and stopped caring about expanding and governing the Empire. This allowed outside forces to put pressure on the Empire and eventually invade and conquer Rome.
The Roman empire became too big and the people outside of the Roman empire started to attack. From then on out, the empire just continued to collapse.
Christianity
the size of their empire was difficult to defend against barbarian invasions.
The inwards movement of Eurasian peoples who took it over.
The accession of Augustus in 28 BCE.
To this day, historians argue over what caused the Roman empire's downfall.
The Roman empire became too big and the people outside of the Roman empire started to attack. From then on out, the empire just continued to collapse.
The downfall of Rome
Christianity
The Holy Roman Empire fell due to a number of social, economic, political,and historical issues that all accumulated around the same time. The Treaties of Westphalia weakened the Holy Roman Empire.
the size of their empire was difficult to defend against barbarian invasions.
The Roman Empire experienced peace and prosperity.
You need to explain how you think that dates can contribute to the fall of an empire. It is events, not dates that contribute to history.
The inwards movement of Eurasian peoples who took it over.
The fall of the Roman Empire.
Charlemagne's empire was called the Empire of the Roman People. This was rather inconvenient, because the East Roman Empire was still operating and WA also called the Empire of the Roman People. So today, historians call Charlemagne's empire the Carolingian Empire and the East Roman Empire of the Middle Ages is called the Byzantine Empire.
The accession of Augustus in 28 BCE.