In 330 CE, the Roman emperor Constantine the Great did something radical: he declared that Rome was no longer the center of the world. In its place, he named a rebuilt city on the Bosphorus strait — the ancient Greek colony of Byzantion, refashioned on a monumental scale — as Nova Roma: New Rome. The name didn't stick for long. The city soon became Constantinopolis, then Constantinople, then Istanbul. But the concept encoded in those two words — that an empire could transplant itself, that a 'new' version of something ancient could claim equal legitimacy — echoed through a thousand years of history that followed.
The peninsula where New Rome would rise had been inhabited for a very long time. Megarian colonists founded Byzantion around 657 BCE, drawn by the extraordinary geography: a triangular headland where the Golden Horn, the Bosphorus, and the Sea of Marmara converge, commanding the narrow waterway between Europe and Asia. The city that grew there was modest by Roman standards — a provincial Greek polis with commercial importance but no imperial pretensions.
That changed in the 3rd century CE when the Roman Empire splintered under the pressure of invasions, economic strain, and military coups. Emperor Diocletian formalized the split by establishing the Tetrarchy, a system of four co-rulers. His own seat was not in Rome but in Nicomedia — the modern city of İzmit, near Istanbul — which served as the Eastern and senior capital. Rome was already losing its monopoly on Roman power before Constantine ever arrived.
Constantine defeated his last rival, the co-emperor Licinius, at the Battle of Chrysopolis on 18 September 324 — fought at the site of what is now the Üsküdar district on Istanbul's Asian shore. Sole emperor at last, he chose Byzantion for his new capital and spent the years from 326 to 330 rebuilding it on a monumental scale, partly modeling the new city on Rome.
The names he gave it in those years reveal the ambition: the Greek Νέα Ῥώμη (Nea Rhome, 'New Rome'); 'the New, second Rome'; 'Byzantine Rome'; 'Eastern Rome'; Roma Constantinopolitana. Constantine used Nicomedia as his interim capital while the construction proceeded, and it was in 330 that the new city was formally dedicated. He died at a villa near Nicomedia on 22 May 337, having ruled from a city that was already being called by a different name — Constantinopolis — though 'New Rome' remained embedded in its identity for centuries.
The name was not just flattery. Constantine structured his new capital to mirror Rome in deliberate ways: seven hills (Rome had seven), a senate, administrative institutions, a hippodrome adjacent to the imperial palace — an urban grammar copied from the original. The claim was that this city was Rome, transplanted and renewed, not merely an eastern outpost of an Italian city.
The Eastern Orthodox Church preserved the title longest. The Ecumenical Patriarch of Constantinople still bears the formal designation 'Archbishop of Constantinople, New Rome, and Ecumenical Patriarch' — a title that stretches an unbroken thread back to the 4th century. Constantinople was the Third Rome in the ecclesiastical imagination, after the first Rome and sometimes before Moscow, which later claimed the title for itself. The concept of a 'New Rome' proved remarkably durable precisely because it encoded the idea that legitimacy could be inherited and reborn.
The city that Constantine called Nova Roma became Constantinople, capital of the Eastern Roman (Byzantine) Empire for more than a thousand years. It survived the fall of the Western Empire in 476, the Plague of Justinian, sieges by Avars and Arabs and Bulgars, crusaders who sacked it in 1204, and a Latin occupation before it was reclaimed by Byzantine rulers. It fell, finally, to Ottoman forces under Sultan Mehmed II in 1453.
The Ottomans ruled it as their capital until 1923, when the newly founded Turkish Republic moved the government to Ankara and renamed the city Istanbul — the name by which most of its inhabitants had called it informally for centuries anyway. Today, standing in what was once the heart of New Rome — near Hagia Sophia, the Hippodrome, the column of Constantine himself — you stand in a place that has been the center of an empire, the seat of a church, and the capital of successive civilizations. Constantine called it new. It turned out to be one of the oldest continuously inhabited cities on earth.
New Rome — today's Istanbul — lies at approximately 41.014°N, 28.956°E on the European coast of the Bosphorus strait. Approaching from Istanbul Airport (LTFM) to the northwest, the city's extraordinary geography becomes clear at altitude: the triangular headland of the old city, flanked by the Golden Horn to the north and the Sea of Marmara to the south, with the Bosphorus defining the eastern edge. The domes and minarets of Hagia Sophia and the Blue Mosque mark the center of ancient Constantinople's ceremonial core. The Bosphorus suspension bridges — First and Second, spanning the strait between Europe and Asia — define the city's lateral extent. Best viewed on approach from the northwest at 5,000 feet or above, which reveals the full triangle of Constantine's chosen peninsula in one sweeping sight line.