The imperial era began in 27 BC, when Octavian was granted the titles of “Augustus” and “Father of the Fatherland” by the Senate, establishing the principate, ending the turmoil of the republic.
The imperial era is divided into three stages:
Early period (27 BC-284 AD), which was the growth period of the Roman Empire, nominally still a republic, but actually an imperial autocracy. In this period, the Roman Empire waged many wars against foreign countries, conquering Carthage, Egypt, Parthia and other regions, reaching its maximum territory.
Middle period (284-395 AD), which was the peak period of the Roman Empire, with unprecedented economic prosperity and cultural brilliance. In this period, Diocletian and Constantine carried out important reforms, recognized the legitimacy of Christianity, moved the capital to Byzantium (renamed Constantinople).
Late period (395-476/1453 AD), which was the decline and division period of the Roman Empire, with sharp social contradictions, frequent civil wars and foreign invasions. In this period, the Roman Empire split into two parts, east and west. The Western Roman Empire collapsed in 476 AD, and the Eastern Roman Empire (also known as the Byzantine Empire) was destroyed by the Ottoman Turkish Empire in 1453 AD.