principate

principate, at Rome, the term often used in preference to ‘empire’ to describe the rule of the Roman emperors after 31 BC from Augustus until (usually) the accession of Diocletian in AD 284. The word designates the period during which the forms at least of republican government were maintained under the princeps. In the words of the English historian Edward Gibbon it was ‘an absolute monarchy disguised by the forms of a commonwealth’. With the accession of Diocletian the senate lost all independent authority and no longer was any attempt made to disguise the monarchical nature of the empire. The period from 284 onwards is often known as the Later Roman Empire.