Constantine gained complete control of the Roman empire in either 314 or 316. Sources differ on the year.
The mass movement of peoples from Eurasia into the Empire overwhelmed the Roman ability to retain control.
Byzantine
Diocletian.
the location of the peninsula contributed to roman control of the mediterranean region.
The Byzantine empire was the Roman empire, merely its eastern counterpart.
The Eastern Empire.
Constantine gained complete control of the Roman empire in either 314 or 316. Sources differ on the year.
The Roman empire was in power when Jesus was crucified.
The Byzantine Empire was actually the part of the Roman Empire that Emperor Constantine still had control of - so technically it came after the Roman Empire
The mass movement of peoples from Eurasia into the Empire overwhelmed the Roman ability to retain control.
success and control
The Roman Empire had extended its control over Western Europe
Mongols
Spain never regained control of the Holy Roman Empire, as it was never under Spanish control in the first place. The Holy Roman Empire was a multi-ethnic complex of territories in central Europe that existed from 800 to 1806, and its emperors were often from various Germanic states. Spain was a powerful kingdom during the empire's existence, particularly in the 16th and 17th centuries, but it was distinct and separate from the Holy Roman Empire.
It's control of the peoples within it and secure border control.
The Roman Empire had been divided into the East Roman Empire, with its capital at Constantinople, and the West Roman Empire, with its capital either at Rome or Ravenna, in 395. The West Roman Empire was in a state of chaos, with various Germanic kingdoms forming, and though they nominally acknowledged the fact that they were in the Roman Empire, for the most part, they were not really under control. In 476, the last emperor of the West Roman Empire was deposed, and the emperor of the East Roman Empire was asked to assume control of the whole. This is the event referred to as the Fall of the Roman Empire. The Roman Senate, which had operated in Rome since before the Roman Republic continued to operate after the purported fall, and its last known act was after the year 600. The East Roman Empire continued to operate until Constantinople fell to the Turks in 1453.