Hagia Sophia Grand Mosque is a mosque and a major cultural and historical site in Turkey’s largest city. Hagia Sophia Grand Mosque was originally built as a Christian cathedral in the 6th century (between 532 and 537) by the Byzantine emperor Justinian I,Its architects were Anthemius of Tralles (Aydın) and Isidore of Miletus and it was considered the epitome of Byzantine architecture and the world’s largest interior space for nearly a thousand years. Today’s Hagia Sophia is the third Hagia Sophia built in the same location. Remnants of the first building did not reach today; some of the remnants of the second building excavated in 1935 can be seen near the entrance of the third one. Third Hagia Sophia brought some architectural deficiency even it was so pretentious in its era; in 558 east part of the dome, and in the earthquake of 869 one of the semi domes collapsed. The building damaged in the earthquake of 1344 was repaired with the special taxes and donations. Hagia Sophia faced the danger of collapsing completely in Ottoman era, but it was saved by the repair and supporting pillars of Mimar Sinan and managed to survive till today.

It became a mosque in 1453 after the Ottoman conquest of Constantinople, and it was adorned with minarets and Islamic calligraphy. It was converted into a museum in 1935 by the Turkish Republic, and it was declared a UNESCO World Heritage Site in 1985 as part of the Historic Areas of Istanbul. In 2020, it was reopened as a mosque by a presidential decree, sparking controversy and criticism from some international organizations and countries. Hagia Sophia Grand Mosque is a symbol of the rich and diverse history of Istanbul, and it attracts millions of visitors every year who admire its stunning dome, mosaics, marble columns, and artworks.

Plan of Hagia Sophia

Magnificent dome in the center is covered with semi domes over its axis; naves on both sides, flood abscissa, inner and outer narthexes following the entrance are the architectural features.

Main venue of Hagia Sophia Grand Mosque is in the measure of 73.50 to 69.50. Dome sitting on pendants and carried by large piers is 55.60 meters high and approximately 31 meters in diameter. The interior of Hagia Sophia Grand Mosque is decorated by 107 columns, 40 below, 67 above. On some of the elegant column headers, there are monograms of Emperor and Empress Theodora.

Hagia Sophia Grand Mosque is famous for its decoration besides architecture.Figured mosaics of Iconoclasm period (726-843) were destroyed, so the mosaic seen belongs to post-Iconoclasm period, dated between 9th and 12th centuries. Mosaic board on Imperial Gate which is the biggest gate of the inner narthex is dated to the end of the 9th century. On the Horologon Gate in the south of the inner narthex a mosaic board from the 10th century, showing Constantine the Great giving the model of city and Justinian giving the model of the church to Mary and Child Jesus, takes place.

Hagia Sophia Grand Mosque receives daylight from 40 windows on flashing of the dome. On the four pendant’s that the dome stands on have figures of four-winged angels. Cubes in the center of the entrance are monolithic marble belonging to the Hellenistic period, brought by Murat III (1574-1595) from Pergamum. Giant plates with 7.5 meters in diameter, hanging from the wall at gallery level are written by calligrapher Kazasker Mustafa Izzet Effendi.

Portrayal of Mary and Child Jesus on the semi dome of apsis is estimated to be the first mosaic to be done after Iconoclasm period.On the apsis vault, partially destroyed board of Archangel Gabriel is seen. On the left of the apsis maksoorah of the sultan made by Fossati in 1849, and on the right of the abscissa pulpit made in the 16th century are noteworthy.

Precious mosaics can be seen in the gallery of Hagia Sophia. This section is reached by a spiral ramp from the north of the inner narthex. There is a mosaic of Emperor Alexander (912-913) in the north gallery. The Empress watched the religious ceremonies in the middle gallery covered by a vault over the narthex. In this regard, it is known as the Empress Lounge.

Southern gallery is entered through a marble known as Heaven’s Gate. On the right after passing the door, Deesis Mosaic with size of 6 and 4, 7 meters from 12th century is one of the famous mosaics of Hagia Sophia. At the end of the gallery, there are two panels showing emperor and empress together with Mary and Jesus.