Roman Republic Augustus Roman Empire pax romana Antoninus Pius Marcus Aurelius Germanic Pictish Scottish Christianity legalised Constantine I imperial persecution Byzantium Istanbul Constantinople Theodosius fall of the Western Roman Empire Platonic Academy of Athens Byzantine Empire Rome law Italy Islam Mediterranean Western Europe Athens Western Roman Empire Plato
Expanding from their base in central Italy beginning in the third century BCE, the Romans gradually expanded to eventually rule the entire Mediterranean Basin and Western Europe by the turn of the millennium. The Roman Republic ended in 27 BCE, when Augustus proclaimed the Roman Empire. The two centuries that followed are known as the pax romana, a period of unprecedented peace, prosperity and political stability in most of Europe. The empire continued to expand under emperors such as Antoninus Pius and Marcus Aurelius, who spent time on the Empire's northern border fighting Germanic, Pictish and Scottish tribes. Christianity was legalised by Constantine I in 313 CE after three centuries of imperial persecution. Constantine also permanently moved the capital of the empire from Rome to the city of Byzantium (modern-day Istanbul) which was renamed Constantinople in his honour in 330 CE. Christianity became the sole official religion of the empire in 380 CE and in 391–392 CE, the emperor Theodosius outlawed pagan religions. This is sometimes considered to mark the end of antiquity; alternatively antiquity is considered to end with the fall of the Western Roman Empire in 476 CE; the closure of the pagan Platonic Academy of Athens in 529 CE; or the rise of Islam in the early 7th century CE. During most of its existence, the Byzantine Empire was one of the most powerful economic, cultural, and military forces in Europe.
