Chora Church, whose name means “countryside,” began as a monastery during the 4th century. At that time, it was located just outside the city walls built by Constantine. By the 5th century, as the city expanded, new walls—the Theodosian walls—were constructed, bringing the monastery within the boundaries of Constantinople.
The building underwent significant changes over the centuries. In the 11th century, it was completely rebuilt. However, disaster struck when an earthquake damaged the structure. The Chora Church seen today, along with its remarkable mosaics, dates mostly from the 14th century, reflecting the rich artistry of that era.
In 1500, the church was converted into a mosque. During this time, the famous mosaics were covered with plaster, hiding them from view. The building’s story changed again in 1958, when it became a museum and the mosaics were carefully restored for visitors to admire.
In 2020, Chora Church was once more designated a mosque. However, unlike some other historical sites, the mosaics here have been preserved because of their cultural importance and the value they bring from tourism. Visitors are welcome, but it is important to plan around prayer times when the mosque is closed to tourists.
Source - https://en.wikipedia.org/wiki/The_Chora