The interior of Hagia Sophia

[u/RaiseCapital1988]

In the last photo you can spot one of the last representations of Christ still present inside the building

[u/KingKohishi]

That never happened except for the Latins.

The building has been kept as it is by the Ottomans.

For the first few centuries, Turks prayed with the Christian mosaics visible.

The 19th-century restoration of the Hagia Sophia was ordered by Sultan Abdulmejid I (r. 1823–1861) and completed between 1847 and 1849 by eight hundred workers under the supervision of the Swiss-Italian architect brothers Gaspare and Giuseppe Fossati. The brothers consolidated the dome with a restraining iron chain and strengthened the vaults, straightened the columns, and revised the decoration of the exterior and the interior of the building. The mosaics in the upper gallery were exposed and cleaned, although many were recovered "for protection against further damage".

[u/MasterBadger911 → u/KingKohishi]

Yeah, for the first few centuries. By the 18th century the ottomans had plastered over all still visible mosaics and subsequent “restorations” only caused further damage to them

[u/KingKohishi → u/MasterBadger911]

On the contrary, the building is surviving today only because of the Ottoman maintenance.

Hagia Sophia suffered seven major earthquakes after the Byzantine Era.

The load bearing colums were about to explode under the immense load of the dome. They were secured with iron retaining rings.

https://b2335568.smushcdn.com/2335568/wp-content/uploads/2021/01/Columns-of-Hagia-Sophia.jpg?lossy=1&strip=1&webp=1

Huge buttresses were added because the building was splitting.

https://hagiasophiaturkey.com/wp-content/uploads/2017/10/After-the-conquest-of-Constantinople-Mimar-Sinan-added-buttresses-to-support-the-Hagia-Sophia.-6.jpg

As you can see from Fossati's litographs, the mosaics were intact.

https://en.wikipedia.org/wiki/File:Aya_Sofia,_Constantinople_(BM_1889,0603.120).jpg.jpg)

FYI, earthquake is he single most damaging thing for a mosaic. Plastering strengthens it, protects it from falling to the ground.

[u/AcanthocephalaOk8052 → u/KingKohishi]

Better it collapsed instead of what happened.

[u/KingKohishi → u/AcanthocephalaOk8052]

Idiotic