Built in late antiquity and the structure central to the early history of Christianity this was the first church to be built in honor of the Virgin Mary and is famous with the Ecumenical Council convened here in the year 431 AD.
Emperor Theodisius II, ordered the convening of the 3rd Ecumenical Council, the first two being in Nicaea in 325 AD, and Constantinople in 381 AD. And it was attended by the Archbishop of Constantinople, Alexandria, Antioch and Ephesus as well as an emissary of the Pope.
Issues fundamental to the Nature of Christianity were debated and many are heated exchange took place over the course of the assembly, which lasted a full 3 months.
The end result was the refutation of Nestorius' notion of Christ and the assertion and declaration of Christ as the Son of God.
After leaving Cyprus, John the Apostle and Virgin Mary are believed to have arrived in Ephesus where they lived and died.
Certain sources states that John the Apostle composed large parts of the Bible here. While being led to the Hill of Golgotha to be crucified Christ entrusted Mary to the care of his most beloved disciple, John the Apostle.
In the phase of persecution the Christians by Herod the Great or the I, John the Apostle and Mary left Jerusalem for Western Anatolia, both to escape persecution in Judea and in order to promulgate the new religion amongst the idolaters.
In this way densely populated cities of Western Anatolia helped spread Christianity to the West and the Roman world making Ephesus a major center of the new religion.