What Were Rome's Problems?
The problems of Rome were many. When Marcus Aurelius died, his son Commodus took over. He was a cruel ruler and wasted money. His bodyguard killed him. Confusion and fighting fallowed. After Commodus, a dynasty of empires ruled called the Severan ruled Rome. They ignored the problems of Rome.
What Changes Did Diocletian & Constantine Make?
Diocletian introduced reform. The empire was so large that he divided it into 4 parts.