Why go
Ephesus, Miletus and ancient Smyrna show the importance of western Anatolia's Greek cities. Istanbul then shifts the focus to Byzantium, chosen as a Roman capital and later known as Constantinople. Together they explain why Roman and Byzantine remains appear across Turkey, while the experience of a coastal city differs from that of an imperial capital.
The full story
Greek settlers founded or developed cities along Anatolia's western coast, including Miletus, Ephesus and Smyrna. Byzantium was founded by Greek colonists beside the strait that now runs through Istanbul. These places became part of wider political and cultural worlds under Persian rule, the conquests of Alexander the Great, and then Rome. The Greek language and culture remained influential across much of Anatolia during the Roman period. The center of Roman power later moved east. Constantine chose Byzantium as a new capital in the fourth century, and the city became known as Constantinople. After the Roman Empire divided, it remained the capital of the eastern empire, which historians call Byzantine. This long continuity is the key to reading Istanbul's older monuments: they belong to a Roman capital that endured for centuries, not to a separate ancient city that appeared overnight. Elsewhere in Anatolia, Roman and Byzantine history overlaps with local traditions and changing frontier regions.