The Kalenderhane Mosque stands as a remarkable testament to Istanbul’s layered history. Originally constructed around the year 1200, it first served as the Eastern Orthodox Church of Theotokos Kyriotissa. This structure showcased the religious and architectural traditions of its time, reflecting the city’s significance in the Byzantine world.
Following the Ottoman conquest of Constantinople, the building’s role changed dramatically. It was given to the Qalandari, a Sufi sect known for its distinct spiritual practices. This transformation marked a new chapter in the building’s life, as it became a place for Sufi gatherings and devotion.
By the mid-18th century, the structure underwent another significant change when it was converted into a Sunni mosque. During this period, many of its original mosaic decorations were covered with plaster, reflecting the artistic and religious shifts of the era.
In the 1970s, efforts began to restore the mosque’s original appearance. Conservation work uncovered mosaics and architectural details that had been hidden for centuries, allowing visitors today to appreciate the blend of Byzantine and Ottoman influences at Kalenderhane Mosque.
Source - https://en.wikipedia.org/wiki/Kalenderhane_Mosque