in the 1420s, before the conversion of its cellar into a mosque The mosque was originally the basement cellar of a
Byzantine fortress. After the
conquest of Constantinople in 1453, this cellar was used as a storage for ammunition, as well as a water cistern. Then the
Ottoman vizier,
Köse Bahir Mustafa Pasha, converted the cellar into a mosque in 1753. Memorial cenotaphs for three holy men were added in the same year as well, at the request of a
Naqshbandi dervish. The
1754 Istanbul earthquake destroyed the structure, and so the Ottoman Sultan
Mahmud I ordered it to be rebuilt. The mosque was thus completed in 1756. The minaret was later rebuilt as well, but it is nowhere to be seen in the present day. == The tombs ==