Alexandria Troas, modern Dalyanköy in Turkey, was almost certainly founded in 306 BC by Antigonus Monophthalmus, who forced the population of at least six villages, together with the island of Tenedos, to settle in a new city that had until then been called Sigia. Its original name was Antigonia, but it was rebaptized and adorned by Lysimachus after the Battle of Ipsus (301). It measured about 2500x1700 meters and was one of the most successful foundations of the early Hellenistic period, and belonged to the Seleucid Empire after the Battle of Corupedium (281).
When the Romans had defeated the Seleucid king Antiochus III the Great in the Syrian War, Alexandria Troas was declared "free and autonomous" (188). After all, it was very close to Troy, the town that was believed to have been the mother-city of Rome. It became wealthier, as is indicated by the building of the temple of Apollo Smintheus. (A dedication mentions a Quintilia who acted as prophetes.) More favors were to come. Julius Caesar gave Alexandria the privileges of a colonia. Under Augustus, it kept the right to strike its own coins. The apostle Paul visited the town.note
Constantine I the Great toyed with the idea to make this city the new capital of the Roman empire, before eventually preferring Byzantium, which became known as Constantinople and eclipsed Alexandria Troas. The city went into decline. Today, there are many ruins, which include an aqueduct, a basilica, a bathhouse (built by Herodes Atticus), temples, a theater, an odeon, and city walls.