The Principate is the name sometimes given to the first period of the Roman Empire from the beginning of the reign of Augustus in 27 BC to the end of the Crisis of the Third Century in AD 284, after which it evolved into the so-called Dominate. The Principate is characterised by the reign of a single emperor (princeps) and an effort on the part of the early emperors, at least, to preserve the illusion of the formal continuance, in some aspects, of the Roman Republic. Etymology and anticipations 'Principate' is etymologically derived from the Latin word princeps, meaning chief or first, and therefore represents the political regime dominated by such a political leader, whether or not he is formally head of state or head of government. This reflects the principate emperors' assertion that they were merely "first among equals" among the citizens of Rome. Under the Republic, the princeps senatus, traditionally the oldest or most honoured member of the Senate, had the right to be heard first on any debate. Scipio Aemilianus and his circle had fostered the (quasi-Platonic) idea that authority should be invested in the worthiest citizen (princeps), who would beneficently guide his compeers, an ideal of the patriot statesman later taken up by Cicero. Duration In a more limited and precise chronological sense, the term Principate is applied either to the entire Empire (in the sense of the post-Republican Roman state), or specifically to the earlier of the two phases of "Imperial" government in the ancient Roman Empire before Rome's military collapse in the West (fall of Rome) in 476 left the Byzantine Empire as sole heir. This early, 'Principate' phase began when Augustus claimed auctoritas for himself as princeps; and continued (depending on the source) up to the rule of Commodus, of Maximinus Thrax, or of Diocletian. Afterwards, Imperial rule in the Empire is designated as the Dominate, which is subjectively more like an (absolute) monarchy while the earlier Principate is still more 'Republican'. History The title, in full, of princeps senatus / princeps civitatis ("first amongst the senators" / "first amongst the citizens") was first adopted by Octavian Caesar Augustus (27 BC–AD 14), the first Roman "emperor" who chose, like the assassinated Julius Caesar, not to reintroduce a legal monarchy. Augustus's purpose was probably to establish the political stability desperately needed after the exhausting civil wars by a de facto dictatorial regime within the