The Roman Empire was ruled by a tetrarchy consisting of two augusti (senior emperors) and two Caesars (junior emperors). The empire was divided into western and eastern territories, with one Augustus and Caesar ruling over each.[2][5] After Diocletian and his colleague, Maximian, retired in 305, internal strife erupted among the tetrarchs. The system finally ceased to exist around 313,[2] and though this form of government was short-lived, it served to separate military and civic leadership roles and was one of the first examples of balanced power