Hagia Sophia isometric elevation (after Rowland J. Mainstone).

The records list a total of 600 persons assigned to serve in Hagia Sophia: 80 priests, 150 deacons, 40 deaconesses, 60 subdeacons, 160 readers, 25 chanters, 75 doorkeepers.

Although there are no artifacts confirming it, it is said that Hagia Sophia was built on the site of an ancient pagan temple. Hagia Sophia underwent two phases of construction before attaining its present state.

Documents indicate that the first Hagia Sophia was built by Emperor Constantius, son of Emperor Constantinos I, and was opened for services in 360 AD. Although very little is known about this church, it is assumed that it was a basilica-type structure with a rectangular floor plan, circular apse and timbered roof. It was similar to St.Studios, a basilica in Istanbul, the ruins of which still exist. Ancient sources emphasize that the eastern wall was circular.

Hagia Sophia — View from the East. The most remarkable feature of the church, which belongs to the transitional type of domed basilica, is the huge dome supported by four massive piers.

View from a window in the precinct of the Sultan Ahmet I Camii (Blue Mosque).

View from the South. The thrust of the huge dome is countered by the two half-domes and the smaller domes, to the east and west, and the massive buttresses to the north and south

Hagia Sophia was first named "Megale Ekklesia" (The Great Church) as it was the largest church in Constantinople. The historian Socrates indicated that the church was named Sophia during the reign of Emperor Constantius. The name given to the church symbolized the second divine attribute of the Holy Trinity. Originally, Sophia, which means "Holy Wisdom", was a name given to Christ by 4th century theologians. Both names, Megale Ekklesia and Hagia Sophia are used today.

Hagia Sophia at Sunset.

Hagia Sophia lithograph from the album by the Fossati brothers, Aya Sofia Constantinople, London 1852, pl. 25 (Athens Gennadeios Library).

Hagia Sophia lithograph from the album by the Fossati brothers, Aya Sofia Constantinople, London 1852,  (Athens Gennadeios Library).

Emperor Theodosius II built a new church which was completed in 415 AD. The architect of this second church was Ruffinos. The edifice was constructed in basilica-style and had five naves. In common with other basilicas of that age, it had a covered roof. The remains of this church, excavated in 1935, show that a staircase of five steps led to a columned propylaeum in front of the entrance of the building. Including the imperial entrance, there were three doorways in the facade. The results of excavations indicate that Hagia Sophia was 60 metres wide. The length is unknown, since further excavations inside the present-day edifice are not permitted.

Hagia Sophia Longitudinal section (Drawing by Giroux after A. Grabar).

Hagia Sophia — (drawn by Giroux after A. Grabar and R. L. Van Nice).

During the rebellion of Monophysites in 532, Hagia Sophia was destroyed along with many other important buildings, among which were the Church of St. Eirene, Zorzip Bath and Samsun Hospital.

After resorting to bloodshed, Emperor Justinian succeeded in saving his throne. This revolt is known as the "Nike Revolt" in Byzantine history, since the rebels repeatedly shouted "Nike", the name of the goddess of victory.

Hagia Sophia interior. View of the vast expanse under the dome and the half-domes.

Hagia Sophia interior. Lithograph from the album by the Fossati brothers, Aya Sofia Constantinople, London 1852, pl. 6 (Athens Gennadeios Library).

Hagia Sophia Interior. Four arches swing across the piers, linked by four pendentives.  The apices of the arches and the pendentives support the circular base of the huge central dome.

The finest and rarest materials from the four corners of the empire were brought to Constantinople to be used in the construction of Hagia Sophia. The prophyry columns previously taken to Rome from an Egyptian temple in Heliopolis, ivory and gold icons and ornaments from ancient temples in Ephesus, Kizikos and Baalbek were among them. The construction was completed in a very short time.

Hagia Sophia Interior. Lithograph from the album by the Fossati brothers, Aya Sofia Constantinople, London 1852,  (Athens Gennadeios Library).

Hagia Sophia interior. View towards the north colonnade and gallery.

The south doorway of the esonarthex before the uncovering of the mosaic in the lunette. Lithograph from the album by the Fossati brothers, Aya Sofia Constantinople, London 1852,  (Athens Gennadeios Library).

Later, the church was damaged many times by earthquakes and fires, and had to be repaired and reinforced.

The south doorway of the esonarthex. The lunette is decorated with a superb mosaic composition of the enthroned Virgin and Child flanked by Constantine the Great who presents a model of the city and Justinian who offers a model of the Church.

South doorway of the esonarthex. The excellent mosaic composition in the lunette showing the enthroned Virgin and Child between the Emperors Constantine the Great and Justinian must have been executed in the reign of Basil II (976-1025), who held in great admiration both these Emperors.

The mosaic in the lunette over the imperial doorway leading from the narthex to the naos (nave) shows Christ enthroned and on either side, enclosed within roundels, the busts of the Holy Virgin and the Archangel Gabriel. To the left a crowned Emperor, commonly identified as Leo VI the Wise (886-912) is shown prostrate before Christ.

On February 9th 869, during the reign of Emperor Basil I (867-886), an earthquake damaged the western side of the building. It was repaired in 870. On October 25th 986, a violent earthquake resulted in the collapse of the western apse and caused partial damage to the dome. The church had to be closed until the architect Tridat finished repairing it in 994.

Mosaic of the Virgin and Child in the apse. The oldest surviving mosaic in Hagia Sophia is that of the Virgin enthroned, “the living throne of Christ Pantocrator,” with the Christ Child in her lap. A work assignable to the second half of the 9th century, it replaced the cross of the iconoclasts in the half-dome of the sanctuary apse.

Mosaic depicting the Empress Zoe (1028-1050) and her third husband, Constantine IX Monomachus (1042-1055), presenting to the enthroned Christ a bag containing gold coins and a scroll inscribed with a list of donations. The composition, along with another dedicatory mosaic panel placed next, illustrates in a most eloquent manner, the association of the Byzantine Emperors with the Great Church.

One of two angels flanking the enthroned Virgin and Child, the only figure of Gabriel executed in splended colors against a gold background, has been partly preserved on the south side of the apse.

In 1317, during the reign of Emperor Andronicus II, the north-eastern and south-western walls were reinforced on the exterior by pyramid-shaped buttresses.

Detail from the mosaic panel of Christ between the Empress Zoe and the Emperor Constantine IX Monomachus. Christ is the dominant figure of the mosaic composition and His depiction on a larger scale than the other two figures is meant to stress the difference between the divine and human natures.

Mosaic of the Emperor John II Comnenus (1118-1143) and his consort Irene presenting a bag of gold coins and a scroll inscribed with a list of donations to the Theotokos. The mosaic composition is completed with the portrait of their son, the pale and frail looking, 17-year old Alexios.

The standing Virgin holds the Christ Child, who makes the sign of the cross of blessing.

When the Turks conquered Constantinople in 1453, the church was converted into a mosque, a place of Islamic worship. To begin with, Turks preserved the frescoes and mosaic figures of Christian saints which decorated the walls. However, in the 16th century, these were completely covered by plaster, since the Islamic code forbids figural representation.

After it became a mosque, the following changes, necessitated by Islamic architectural standards, were made:

Sultan Mehmed II "the Conqueror" built an altar (mihrap) in the east, since the apse should be in the direction of Mecca and the brick minaret on the south-east corner of the edifice.

Sultan Bayezid (1484-1512) added a minaret on the north-east corner.

Detail of the mosaic in the lunette over the south doorway showing Justinian who presents a model of the church of Hagia Sophia to the Virgin and Child.

Mosaic of the Deesis. The large mosaic composition, occupying the entire south side of the so-called “Catechumena” is representative of the new trends and conceptions prevailing in the 13th century at Constantinople and was probably comissioned after the restoration to express the gratitude of the City for the victory of Michael VII Paleologos (1261-1282) over the Latins.

Detail of the mosaic of the Deesis — At the center of the composition, Christ is shown holding a closed Book of the Gospels and making the sign of the benediction. The iconographic type appears renewed, the expression is that of the so-called Palaeologan Christ, revealing God’s compassion for humanity

The pulpit (minber) and preacher's pew (muezzin mahfili) were added to the interior during the reign of Murad IV.

In 1739, Sultan Mahmud I built a library and a primary school (mekteh-i sibyan) in the south.

In 1850, Sultan Abdulmecit added the present day Imperial Pew. During his reign (1833-1861), important repairs were entrusted to the Swiss architect Gaspare Fossati. He removed the plaster covering the mosaics and then replastered them. He decorated these newly plastered areas with frescoes. The building was completely renovated inside and out. An horologion was built to the south of the structure.

In 1926, the government of the new Republic of Turkey, appointed a technical commission to investigate the architectural and static state of the building thoroughly. According to the commission's report, the foundation of the structure rested solidly on a bed of rock. Following Kemal Ataturk's orders, Hagia Sophia was converted into a museum on February 1st 1935. Ataturk visited the museum a few days later, on February 6th 1935.

Mosaics of St. John Chrysostom and St. Ignatius of Antioch. Two of the 14 bishops and 16 prophets portrayed in the blind arches above the galleries of the north and south sides. A third surviving figure is that of the Patriarch Ignatius the Younger, the well-known opponent of the Patriarch Photios I. Portrayals of Patriarchs are not uncommon in the decoration of churches and other public buildings.

The magnificent mosaic composition of the Deesis showing Christ between the Holy Virgin and St. John the Baptist. The mosaic is executed in fine tesserae of soft hues and the figures are set against a background of gold. The wistful and grave expressions reflect a profound spirituality and announce a new epoch marked by high aesthetic standards and classical trends. At the same time, they signal the general feeling of insecurity caused by the fluid state of affairs and the uncertainty of the Empire’s future