Hagia Sophia was rebuilt in her present pattern between 532 and 537 under the personal supervision of Emperor Justinian I. It is one of the greatest surviving examples of Byzantine architecture, wealthy with mosaics and marble pillars and coverings. After culmination, Justinian is said to have called out, Ne?????? se S???µ?? ("Solomon, I have outdone thee!")The architects of the place of adoration were Isidore of Miletus and Anthemius of Tralles, who were professors of geometry at the University of Constantinople.(Mainstone, 1997) Their work was a mechanical triumph, even though the structure was severely impaired several times by earthquakes. The initial dome collapsed after an earthquake in 558 and its replacement dropped in 563. Steps were taken to better secure the dome, but there were added partial collapses in 989 and 1346
Justinian's basilica was both the culminating architectural achievement of Late Antiquity and the first masterpiece of Byzantine architecture. Its leverage, both architecturally and liturgically, was widespread and enduring in the Eastern Orthodox, Roman Catholic, and Muslim worlds alike. (Mainstone, 1997)
For over 900 years the Hagia Sophia was the seat of the Orthodox Patriarch of Constantinople and a primary setting for church councils and imperial ceremonies. In 1204 the cathedral was ruthlessly assaulted, desecrated and plundered by the Crusaders, who also ousted the Patriarch of Constantinople and restored him with a Latin bishop. This happening cemented the division of the Greek Orthodox and Roman Catholic churches that had started with the Great Schism of 1054. It also means that most of Hagia Sophia's riches can be seen today not in Istanbul, but in the treasury of St. Mark's Basilica in Venice.
Despite this brutal setback, Hagia Sophia stayed a functioning place of adoration until May 29, 1453, when Sultan Mehmet the Conqueror went into triumphantly into the town of Constantinople. He was astonished at the attractiveness of the Hagia Sophia and directly altered it into his imperial mosque. (Swainson,2007)
The most famous restoration of the Hagia Sophia was accomplished between 1847-49 by Abdülmecid II, who asked for Swiss architects Gaspare and Guiseppe Fossati to renovate the mosque. The brothers consolidated the dome and vaults, straightened columns,and revised the adornment of the exterior and the interior.In 1934, under Turkish president Kemal Atatürk, Hagia Sofia was secularized and turned into the Ayasofya Museum. The plea rugs were taken, disclosing the marble under, but the mosaics stayed mostly plastered over and the construction was permitted to breakdown for some time. Some of the calligraphic panels were shifted to other mosques, but eight roundels were left and can still be seen today.(Swainson,2007)
A 1993 UNESCO mission to Turkey documented dropping plaster, soiled marble facings, broken windows, adorning paintings impaired by moisture, and ill-maintained lead roofing. Cleaning, roofing and restoration have since been undertaken; numerous latest visitors have discovered their outlook obstructed by a gigantic scaffolding stretching up into the dome in the center of the nave.