330 – 340s

Events in the 330s 5

• 306 – 337 Constantine the Great Constantine I reunites the empire after defeating his rivals — culminating in the defeat of Maxentius at the Milvian Bridge (312 AD), where Constantine reportedly sees a cross in the sky with the words "In this sign, conquer." Whether genuine vision or political calculation, Constantine legalises Christianity with the Edict of Milan (313 AD), convenes the Council of Nicaea (325 AD) and founds Constantinople (330 AD) as the empire's new capital on the Bosphorus. His conversion transforms Western history.
• 330 – 1453 Byzantine Empire The Byzantine Empire -- the Eastern Roman Empire -- endured for 1,123 years from the founding of Constantinople by Constantine the Great in 330 AD to its fall to the Ottoman sultan Mehmed II on 29 May 1453. At its height under Justinian I (527-565) it controlled the Mediterranean basin from Spain to Mesopotamia. It was the largest and most sophisticated state in the medieval world, preserving Greek and Roman knowledge through the Dark Ages, spreading Orthodox Christianity to the Slavic world, and providing the institutional and cultural framework from which modern Europe emerged. Its capital Constantinople was the greatest city in Christendom for nearly a millennium.
• 330 – 610 The Early Empire (330–610) The Early Byzantine period spans from Constantine's founding of Constantinople to the death of Maurice and the accession of Heraclius. It encompasses the Christianisation of the Roman Empire, the fall of the West (476), Justinian's great reconquest of North Africa and Italy, the construction of Hagia Sophia, the Plague of Justinian (the first pandemic in recorded history), and the exhausting Persian wars that leave both empires vulnerable to the Arab conquests. This is the period in which the Roman Empire becomes the Byzantine Empire -- Greek in language and culture, Orthodox in religion, but Roman in law and institutional identity.
• 330 Constantinople founded On 11 May 330 AD, Constantine dedicates his new capital — Constantinople — on the site of the Greek city Byzantium, at the strategic junction of Europe and Asia. The city is designed as a new Rome: it has seven hills, a Forum, a Senate, a hippodrome and grain doles. Its position on the Bosphorus makes it almost impregnable by land and sea. Constantinople will serve as the capital of the Eastern Roman (Byzantine) Empire for 1,123 years — until its fall to the Ottomans in 1453.
• 330 Constantinople founded Constantine the Great dedicates Constantinople on 11 May 330 AD on the site of the Greek city Byzantium, at the strategic junction of Europe and Asia on the Bosphorus. Designed as a new Rome with seven hills, a Senate, a Forum, a hippodrome and grain doles, the city is virtually impregnable by land and sea. It will serve as the capital of the Eastern Roman Empire for 1,123 years.