Hagia Sophia is a former patriarchal basilica, later a mosque, now a museum, in Istanbul. Famous in particular for its massive dome, it is considered the epitome of Byzantine architecture and one of the most beautiful buildings in the world. It was the largest cathedral in the world for nearly a thousand years, until the completion of the Medieval Seville Cathedral in 1520.
The current building was originally constructed as a church between 532 and 537 on the orders of the Byzantine Emperor Justinian, and was in fact the third Church of the Holy Wisdom to occupy the site (the previous two had both been destroyed by riots). It was designed by two architects, Isidore of Miletus and Anthemius of Tralles. The Church contained a large collection of holy relics and featured, among other things, a 50-foot (15 m) silver iconostasis. It was the patriarchal church of the Patriarch of Constantinople and the religious focus point of the Orthodox Byzantine Empire for nearly 1000 years.
In 1453, Constantinople was conquered by the Ottoman Turks and Sultan Mehmed II ordered the building to be converted into a mosque. The bells, altar, iconostasis, and sacrificial vessels were removed, and many of the mosaics were eventually plastered over. The Islamic features - such as the four minarets outside, the mihrab and minbar - were added over the course of its history under the Ottomans. It remained as a mosque until 1935, when it was converted into a museum by the secular Republic of Turkey.
For almost 500 years the principal mosque of Istanbul, Hagia Sophia served as a model for many of the Ottoman mosques such as the Sultan Ahmed Mosque (Blue Mosque of Istanbul), the Şehzade Mosque, the Süleymaniye Mosque, and the Rüstem Pasha Mosque.
Although it is sometimes referred to as Saint Sophia, the Greek name in full is Church of the Holy Wisdom of God and it was dedicated to the Holy Wisdom of God rather than a specific saint named Sophia.
Nothing remains of the first church that was built on this location, known as the Megalè Ekklèsia (Great Church), or in Latin "Magna Ecclesia". It was built next to the area where the imperial palace was being developed and next to the smaller church Hagia Eirene, finished first and acting as cathedral until the Hagia Sophia was completed. The Hagia Sophia was inaugurated by Constantius II on 15 February 360. Both churches acted together as the principal churches of the Byzantine Empire.
This church was chronicled by Socrates of Constantinople (380-440), who claimed that it was built by Constantine the Great. It was built as a traditional Latin colonnaded basilica with galleries and a wooden roof. It was preceded by an atrium. This first church was then already claimed to be one of the world's most outstanding monuments. The appellation "Megalo Ecclesia" continued to be used for a long time, only to be replaced by the name "Hagia Sophia" after the conquest of Byzantium in 1453.
The patriarch of Constantinople John Chrysostom came into a conflict with Empress Aelia Eudoxia, wife of the Emperor Arcadius and was sent into exile on 20 June 404. During the subsequent riots, this first church was largely burned down. A second church was ordered by Theodosius II, who inaugurated it on 10 October 405. The fire that started during the tumult of the Nika Revolt, resulted in the destruction of the (second) Hagia Sophia that burned down to the ground on 13-14 January 532. Several marble blocks of this second church have survived to our date, and are displayed in the garden of the current (third) church. These marble slabs were excavated in the western courtyard by A.M. Schneider in 1935. They were part of a monumental front entrance.
On 23 February 532, only a few days after the destruction of the second basilica, Emperor Justinian I took the decision the build a third and entirely different basilica, larger and more majestic than its predecessors. He appointed the architects Isidorus and Anthemius.
Justinian chose the physicist, Isidore of Miletus and the mathematician, Anthemius of Tralles as architects; Anthemius, however, died within the first year. The construction is described by the Byzantine historian Procopius' On Buildings (De Aedificiis). The emperor had material brought over from all over the empire, such as Hellenistic columns from the temple of Artemis at Ephesus. Large stones were brought from far-away quarries : porphyry from Egypt, green marble from Thessaly, black stone from the Bosphorus region and yellow stone from Syria. More than ten thousand people were employed during this construction. This new church was immediately recognized as a major work of architecture, demonstrating the creative insights of the architects. They may have used the theories of Heron of Alexandria to be able to construct a huge dome over such a large open space. The emperor, together with the patriarch Eutychius, inaugurated the new basilica on December 27, 537 with much pomp and circumstance. The mosaics inside the church were, however, only completed under the reign of Emperor Justin II (565-578).
Earthquakes in August 553 and on 14 December 557 caused cracks in the main dome and the eastern half-dome to appear. The main dome collapsed completely during an earthquake on 7 May 558, destroying the ambon, the altar and the ciborium over it. The emperor ordered an immediate restoration. He entrusted it to Isodorus the Younger, nephew of Isidore of Miletus. This time he used lighter materials and elevated the dome by 6.25 meters, thus giving the building its current interior height of 55.60 meters. . This reconstruction, giving the church its present sixth-century form, was completed in 562. The Byzantine poet Paul the Silentiary composed an extant, long epic poem, known as Ekphrasis, for the rededication of the basilica on 23 December 562.
Hagia Sophia was the seat of the Orthodox patriarch of Constantinople and a principal setting for Byzantine imperial ceremonies, such as crowning ceremonies. The basilica also offered asylum to wrongdoers. Foreign visitors were deeply impressed.
In 726 the Emperor Leo the Isaurian issued a series of edicts against the worship of images (iconoclasm), ordering the army to destroy all icons. At that time, all religious pictures and statues were removed from the Hagia Sophia. After a brief reprieve under Empress Irene (797-802), the iconoclasts made a comeback. Emperor Theophilus (829-842) was strongly influenced by the Islamic art, forbidding graven images. He had a two-winged bronze door with his monograms installed at the southern entrance of the church.
The basilica suffered damage, first by a great fire in 859, and again by an earthquake on 8 January 869 that made a half-dome collapse. Emperor Basil I ordered the church to be repaired.
After the great earthquake of 25 October 989, which ruined the great dome of Hagia Sophia, the Byzantine emperor Basil II asked for the Armenian architect Trdat, creator of the great churches of Ani and Agine, to repair the dome. His main repairs were to the western arch and a portion of the dome. The extent of the church's destruction meant that reconstruction lasted six years. The church was re-opened on 13 May 994.
In his book De Ceremoniis aulae Byzantinae (Book of Ceremonies), emperor Constantine VII (913-919) wrote about all the details of the ceremonies held in the Hagia Sophia by the emperor and the patriarch.
At the capture of Constantinople during the Fourth Crusade, the church was ransacked and desecrated. The Byzantine Greek historian Nicetas Choniates described the capture of Constantinople. Many relics from the church, such as a stone from the tomb of Jesus, the Virgin Mary's milk, the shroud of Jesus, and bones of several saints, were sent to churches in the West and can be seen now in various museums in the West. During the Latin occupation of Constantinople (1204–1261) the church became a Roman Catholic cathedral. Baldwin I of Constantinople was crowned emperor on 16 May 1204 in the Hagia Sophia, at a ceremony which closely followed Byzantine practices. Enrico Dandolo, the Doge of Venice who commanded the sack and invasion of the city by the Latin Crusaders in 1204, is buried inside the church. The tomb inscription carrying his name, which has become a part of the floor decoration, was spat upon by many of the angry Byzantines who recaptured Constantinople in 1261. However, restoration carried out during the period 1847-1849 cast doubt upon the authenticity of the doge's grave. It is more likely a symbolic burial site to keep alive his memory.
After the recapture in 1261 by the Byzantines, the church was in a dilapidated state. The four buttresses in the west were probably built during this time. In 1317, emperor Andronicus II ordered four new buttresses to be built in the eastern and northern parts of the church. After new cracks had developed in the dome after the earthquake of October 1344, several parts of the building collapsed on 19 May 1346. After that, the church remained closed until 1354, when repairs were undertaken by the architects Astras and Peralta.
Immediately after the Turks conquered Constantinople (Istanbul) in 1453, the Hagia Sophia was converted to a mosque. At that time, the church was very dilapidated. Several of its doors had fallen off. This condition was described by several Western visitors, such as the Cordoban nobleman Pero Tafur and the Florentine Cristoforo Buondelmonti. The sultan Mehmed the Conqueror ordered the immediate cleanup of the church and its conversion to a mosque. The next sultan Beyazid II built a new minaret, replacing the one built by his father.
In the 16th century the sultan Suleiman the Magnificent (1520-1566) brought back two colossal candles from his conquest of Hungary. They were placed on both sides of the mihrab. During the reign of Selim II (1566-1577), the building started showing signs of fatigue and was extensively strengthened with the addition of structural supports to its exterior by the great Ottoman architect Sinan, who is also considered one of the world's first earthquake engineers. In addition to strengthening the historic Byzantine structure, Sinan built the two additional large minarets at the western end of the building, the original sultan's loge, and the mausoleum of Selim II to the southeast of the building (then a mosque) in 1577. The mausoleums of Murad III and Mehmed III were built next to it in the 1600s.
Later additions were the sultan's gallery, a minbar decorated with marble, a dais for a sermon and a loggia for a muezzin.
The sultan Murad III (1574-1595) had two large alabaster Hellenistic urns transported from Pergamon and placed on two sides of the nave.
Sultan Mahmud I ordered the restoration of the building in 1739 and added a medrese (a Koranic school, now the library of the museum), a soup kitchen (for distribution to the poor) and a library, and in 1740 a fountain for ritual ablutions (Şadirvan), thus transforming it into a külliye, i.e. a social complex. At the same time a new sultan's gallery and a new mihrab were built inside.
The most famous restoration of the Hagia Sophia was ordered by Sultan Abdülmecid and completed by eight hundred workers between 1847 and 1849, under the supervision of the Swiss-Italian architect brothers Gaspare and Giuseppe Fossati. The brothers consolidated the dome and vaults, straightened the columns, and revised the decoration of the exterior and the interior of the building. The mosaics in the upper gallery were cleaned. The old chandeliers were replaced by new pendant ones. New gigantic circular-framed disks were hung on columns. They were inscribed with the names of Allah, the prophet Mohammed, the first four caliphs Abu Bakr, Omar, Osman and Ali and the two grandchildren of Mohammed : Hassan and Hussain, by the calligrapher Kazasker İzzed Effendi (1801-1877). In 1850 the architect Fossati built a new sultan's gallery in a Neo-Byzantine style connected to the royal pavilion behind the mosque. Outside the Hagia Sophia, a timekeeper's building and a new medrese were built. The minarets were altered so that they were of equal height. When the restoration was finished, the mosque was re-opened with ceremonial pomp on 13 July 1849.
In 1935, the first Turkish President and founder of the Republic of Turkey, Mustafa Kemal Atatürk, transformed the building into a museum. The carpets were removed and the marble floor decorations appeared for the first time in centuries, while the white plaster covering the mosaics was painstakingly removed by expert restorers.
Hagia Sophia is one of the greatest surviving examples of Byzantine architecture. Of great artistic value was its decorated interior with mosaics and marble pillars and coverings. The temple itself was so richly and artistically decorated that Justinian proclaimed "Solomon, I have surpassed thee!" . Justinian himself had overseen the completion of the greatest cathedral ever built up to that time, and it was to remain the largest cathedral for 1,000 years up until the completion of the cathedral in Seville.
Justinian's basilica was at once the culminating architectural achievement of late antiquity and the first masterpiece of Byzantine architecture. Its influence, both architecturally and liturgically, was widespread and enduring in the Eastern Orthodox, Roman Catholic, and Muslim worlds alike. Under Justinian's orders, eight Corinthian columns were disassembled from Baalbek, Lebanon and shipped to Constantinople for the construction of Hagia Sophia
The vast interior has a complex structure. The vast nave is covered by a central dome which has a maximum diameter of 31.24 meters and a height from floor level of 55.60 meters, about one fourth smaller than the dome of the Pantheon. The dome seems rendered weightless by the unbroken arcade of 40 arched windows under it, which help flood the colourful interior with light. Due to consecutive repairs in the course of its history, the dome has lost its perfect circular base and has become somewhat elleptical with a diameter varying between 31.24 and 30.86 m.
The dome is carried on pendentives — four concave triangular sections of masonry which solve the problem of setting the circular base of a dome on a rectangular base. At Hagia Sophia the weight of the dome passes through the pendentives to four massive piers at the corners. Between them the dome seems to float upon four great arches.