Answer:
Divided the empire into two halves
Step-by-step explanation:
At the time when Diocletian came to power, the Roman Empire was in severe decline. He began many reforms to undo the turmoil of the last century but he is most memorable for splitting Rome into two pieces. The Eastern Roman Empire that was under him, and the Western Roman Empire that was under the rule of his colleague Maximian. He essentially saved Rome from total collapse.