The Concept of Diarchy

The term 'Diarchy' refers to the joint rule of two emperors, specifically Diocletian and Maximian, from 286 to 293 AD. Unlike previous examples of co-emperors, this period is emphasized by modern scholars as significant because it sets the stage for the later Tetrarchy, a system of four rulers. The distinction is made to highlight that while other pairs of emperors existed, their rule was not labeled as a diarchy; instead, it was the establishment of the Tetrarchy that led to this convenient categorization. The implications of having both emperors acknowledge the need for a cohesive leadership structure are crucial, indicating a strategic alliance to balance power across the vast Roman Empire.