Byzantine era (395-1071)

Ephesus remained the most important city of the Byzantine Empire in Asia after Constantinople in the 5th and 6th centuries. The emperorConstantine I rebuilt much of the city and erected a new public bath. In 406 John Chrysostom, archbishop of Constantinople, ordered the destruction of the Temple of Artemis. Emperor Flavius Arcadius raised the level of the street between the theatre and the harbour. The basilica of St. John was built during the reign of emperor Justinian I in the sixth century.

The town was again partially destroyed by an earthquake in 614.

The importance of the city as a commercial center declined as the harbor was slowly silted up by the river (today, Küçük Menderes) despite repeated dredging during the city's history. (Today, the harbor is 5 kilometers inland). The loss of its harbor caused Ephesus to lose its access to the Aegean Sea, which was important for trade. People started leaving the lowland of the city for the surrounding hills. The ruins of the temples were used as building blocks for new homes. Marble sculptures were ground to powder to make lime for plaster.

Sackings by the Arabs first in the year 654-655 by caliph Muawiyah I, and later in 700 and 716 hastened the decline further.

When the Seljuk Turks conquered Ephesus in 1090, it was a small village. The Byzantines resumed control in 1100 and changed the name of the town to Hagios Theologos. They kept control of the region until 1308. Crusaders passing through were surprised that there was only a small village, called Ayasalouk, where they had expected a bustling city with a large seaport. Even the temple of Artemis was completely forgotten by the local population.

Turkish Era

The town was conquered in 1304 by Sasa Bey, an army commander of the Menteşoğulları principality. Shortly afterwards, it was ceded to theAydınoğulları principality that stationed a powerful navy in the harbour of Ayasuluğ (the present-day Selçuk, next to Ephesus). Ayasoluk became an important harbour, from whence the navy organised raids to the surrounding regions.

The town knew again a short period of flourishing during the 14th century under these new Seljuk rulers. They added important architectural works such as the İsa Bey Mosque, caravansaries and Turkish bathhouses (hamam).

They were incorporated as vassals into the Ottoman Empire for the first time in 1390. The Central Asian warlord Tamerlane defeated the Ottomans in Anatolia in 1402, and the Ottoman sultan Bayezid I died in captivity. The region was restored to the Anatolian Turkish Beyliks. After a period of unrest, the region was again incorporated into the Ottoman Empire in 1425.

Ephesus was eventually completely abandoned in the 15th century and lost her former glory. Nearby Ayasuluğ was renamed Selçuk in 1914.

Ephesus and Christianity

Ephesus was an important center for Early Christianity from the AD 50s. From AD 52-54, Paul lived in Ephesus, working with the congregation and apparently organizing missionary activity into the hinterlands. He became embroiled in a dispute with artisans, whose livelihood depended on selling the statuettes of Artemis in the Temple of Artemis (Acts 19:23–41). He wrote between 53 and 57 AD the letter 1 Corinthians from Ephesus (possibly from the "Paul tower" close to the harbour, where he was imprisoned for a short time). Later Paul wrote the Epistle to Ephesians while he was in prison in Rome (around 62 AD).

Roman Asia was associated with John, one of the chief apostles, and the Gospel of John might have been written in Ephesus, c 90-100.^[26]Ephesus was one of the seven cities addressed in Revelation (2:1–7), indicating that the church at Ephesus was strong.

Two decades later, the church at Ephesus was still important enough to be addressed by a letter written by Bishop Ignatius of Antioch to the Ephesians in the early 2nd century AD, that begins with, "Ignatius, who is also called Theophorus, to the Church which is at Ephesus, in Asia, deservedly most happy, being blessed in the greatness and fullness of God the Father, and predestinated before the beginning of time, that it should be always for an enduring and unchangeable glory" (Letter to the Ephesians). The church at Ephesus had given their support for Ignatius, who was taken to Rome for execution.

The house of the Virgin Mary, about 7 km (4 mi) from Selçuk, is believed to have been the last home of Mary, mother of Jesus. It is a popular place of pilgrimage which has been visited by three recent popes.

The Church of Mary close to the harbor of Ephesus was the setting for the Third Ecumenical Council in 431, which resulted in the condemnation of Nestorius. A Second Council of Ephesuswas held in 449, but its controversial acts were never approved by the Catholics. It came to be called the Robber Council of Ephesus or Robber Synod of Latrocinium by its opponents.