It was the first church which was built in the name of Virgin Mary, the building is also called as the Double Church. The reason that it is called as Double Church is one part of the church was for Mother Mary and the other was for John the Apostle. The Ephesian Christian priest were educated in this church.
The Church of Mary was built during the reign of Constantine the Great 4.century AD. because the structure has the architectural style of this period. It was a classical type basilica structure in rectangular. The entrance by a large atrium was provided, paved with large marble blocks which were brought from other buildings of the city. On the northern side of the atrium there was a niched baptistery of octagonal shape with a baptism chamber covered in marble resembling a “tholos”, and a pool was added to this structure, built in the middle of the floor for baptism of adults. One of the best-preserved baptism of Asia Minor pool is still visible on te northern part. The nartheks was ornamented with mosaics as well as the walls with rosettes and crosses. The Church of Mary was also used as a public meeting house.
In Church of Mary third Council gathered on the 22nd of June 431. 195 Bishops participated in this Council where, amongst other issues, they discussed the divine and human nature of Jesus Christ. Church of Virgin Mary in Ephesus definitely gained a good reputation for housing the deliberation of this Ecumenical Council. While some bishops were supporting the idea that Mary gave birth to God considering Christ had the nature of both God and man, it was firmly not accepted by the some others. The Bishop of Constantinople, Nestorius and his supporters thought that the term Theotokos would threaten the depth of the respect for God so they decided that it would be more appropriate to call Mary as “Christotokos”. The Patriarch of Alexandria, Cyrillus, defended the understanding that Jesus Christ had one personality buy two entities and Mary was actually the Mother of God. In conclusion, the views of Cyrillus were favored and theology that stated Jesus Christ dad a divine form and Mary was the Mother of God were confirmed by this Ecumenical Council.