Abu Ayyub al-Ansari
After the Fall of Constantinople to the Ottomans in 1453, between the end of the 15th and the beginning of the 16th century the church was converted into a small mosque (Mescid) by Toklu Ibrahim Dede, a former soldier of Mehmed the Conqueror, who was the custodian of the nearby "türbe" of Ebû Șeybet ül Hudrî, like the more famous Abu Ayyub al-Ansari (the standard bearer of Muhammad), a companion of the Prophet. Both died during the first Arab siege of Constantinople and were buried outside the wall of Heraclius. The "türbe" of Ebû Șeybet ül Hudrî is now placed in the citadel between the Wall of Heraclius and that of Leo the Armenian.