The Holy Roman Empire encompasses less territory than the Roman Empire. After the fall of the Roman Empire, the empire was divided into the west (Byzantine empire) and east. More warfare ensued and eventually the Holy Roman Empire was established, but this time it mostly consisted of what the Roman Empire used to call savages (Germanic/Franks people) so basically the area that is today Germany, France etc. The Holy Roman Empire never conquered the entire Italian peninsula of today, which the Roman Empire did.
Explanation:
Warfare, overextension, corruption of the Roman Empire lead to its downfall and the Roman Empire was never established to its great success.
