Why is the Roman Empire divided into two Periods – the Principate and the Dominate?

• Historians divide the Roman Empire into two Periods called the ‘Principate’ and the ‘Dominate’, which are also known as the Early Roman Empire (27BCE-284 CE) and the Late Roman Empire (284-476 CE).
• The Principate was a Monarchy, but great care was taken by the Emperors to preserve the impression that the Institutions of the Roman Republic still existed. After 284 CE, all pretence of a Republic was abandoned in favour of an Absolute Monarchy, the Dominate.

The Principate

• The Principate is the period between 27 BCE until 284 CE, also known as the Early Roman Empire.
  • Augustus changed the Roman Constitution to a Monarchy by being granted the Title of ‘Princeps’ meaning ‘First Citizen’ and being granted in perpetuity the Office of ‘Princeps Senatus’ meaning ‘Leader of the Senate’.
  • This was to to avoid being called Dictator with its bad image amongst the Roman Senate, who associated it with the lifetime Dictatorship of Julius Caesar.
  • Also Augustus wanted to give the impression of continuing with the Institutions of the Roman Republic.
  • The title ‘Princeps’ was used by successive Emperors up until Diocletian (284-305 CE).

The Dominate

• The Dominate is the period between 284-476 CE, also known as the Late Roman Empire.
  • Diocletian (284-305 CE) changed the Roman Constitution after 284 CE to become an Absolute Monarchy, with the Emperor as the supreme source of Power. All pretence of continuing the Institutions of the Roman Republic was abandoned.
  • The title Dominate is derived from ‘Dominus’, meaning ‘Lord’ or ‘Master’.
  • Diocletian (284-305 CE) preferred to use the title ‘Dominus’ instead of ‘Princeps’.
  • However, the Roman Republic was never officially abolished and continued to exist until 476 CE.

The Title of 'Imperator'

• The title of Roman Emperor is a convention used by modern historians and did not exist during the Roman Empire.
• Magistrates and Governors of Provinces would exercise their Imperium using the title ‘Imperator’, which meant Commander in Chief.
• The title of Imperator was also a title of honour during the Republic given to Roman Commanders after a victory. Roman Generals would have to be declared ‘Imperator’ by their Legions after a great victory, before they could receive a Roman Triumph.
• The Roman Emperors permanently took the title of ‘Imperator’ to show that they had legal Command of the Legions and of the Roman Government.