WORLD CIVILIZATION

Detailed explanation-1: -The Roman Empire had become too large to be ruled by one emperor by the third century (this was one of the causes of the Crisis of the Third Century). It was divided, by Emperor Diocletian, into a tetrarchy.

Detailed explanation-2: -Diocletian also restructured the Roman government by establishing the Tetrarchy, a system of rule in which four men shared rule over the massive Roman Empire. The empire was effectively divided in two, with an Augustus and a subordinate Caesar in each half.

Detailed explanation-3: -Diocletian delegated further on 1 March 293, appointing Galerius and Constantius as junior co-emperors (each with the title Caesar), under himself and Maximian respectively. Under the Tetrarchy, or “rule of four", each emperor would rule over a quarter-division of the empire.

Detailed explanation-4: -The Tetrarchy was established in 293 CE by the Emperor Diocletian. It consisted of four different rulers, two head emperors (originally Diocletain and Maximian) and two junior emperors (originally Constantius and Galerius). These four Emperors spit the empire into four districts and each ruled separately.