The Roman Empire did not just fall one day. Instead, it slowly declined over several hundred years.
During these years of decline, emperors attempted to make reforms or changes to make things better to prevent the Roman Empire from completely falling apart.
Emperor Diocletian: In 284 CE, he decided that the empire was too large and should be split into an Eastern and Western province. Each province would have its own emperor. Diocletian kept the wealthy Eastern province for himself and gave the weaker and poorer province to another emperor.
During these years of decline, emperors attempted to make reforms or changes to prevent the Roman Empire