In the 1st cent. CE a port at the mouth of the River Cayster on the west coast of Asia Minor. Today it is Seljuk in Turkey; because of silting, it lies about 5 km. (3 miles) from the sea. In the course of six centuries it passed through a succession of Greek, Persian, and Roman regimes and in the era of the NT (where it is mentioned some twenty times) the site was the fourth largest in the empire—prosperous, with splendid streets lined with colonnades, and a temple dedicated to Artemis (Diana) which was one of the seven wonders of the ancient world.
Paul took advantage of the constant traffic across to Corinth. He travelled to and fro (2 Cor. 12: 14; 13: 1) and the Corinthian correspondence was penned in Ephesus. Not that all was calm and uninterrupted; once ‘he fought with beasts’ at Ephesus (1 Cor. 15: 32), either literally or metaphorically; and a mass meeting of protest was staged in the theatre when Demetrius, convener of the silversmiths' union, urged that the propagation of Paul's monotheism was putting in jeopardy their lucrative trade in statues of the great goddess. On this occasion the asiarchs (appointed to promote emperor worship) were minded to sympathize with Paul for breaking the Artemis monopoly (Acts 19: 31). Nevertheless, Paul discreetly said farewell and sailed for Greece, leaving behind an established Church—Aquila and Priscilla among the members—with elders (Acts 20: 17). The Church was destined for a long history: the gospel of John may have been written there by ‘John the Elder’ (of 2 and 3 John?): even the seer of Rev. (2: 1–7) gives it a favourable review, and in 431 CE the Church Council which condemned the heresy of Nestorius was held there.