This emperor realized the roman empire was too large for one man to rule well.
maximinus
diocletian
constantine
theodosius

Correct answer choice is :

Diocletian ended the era recognized as the Crisis of the Third Century. He worked to return Rome to its former majesty by making reforms in key areas. He imprisoned Christians, executing more than any other emperor. He forced the classical polytheistic religion of the Romans. Diocletian also made on Aurelian's economic changes. Although, many of the obstacles of the crisis civil war, barbarian attacks, disease, and economic problems would remain to trouble the empire for centuries to come and begin to the fall of the Western Roman Empire in the fifth century.