In all there are some 40 Byzantine-era church structures still standing throughout Istanbul. However, no matter which one you visit, one feature in particular strikes the visitor: they all either have minarets, or a ticket box, or both. Astonishingly, of the dozens of extant Byzantine churches in Istanbul, only one of them has never been converted into a mosque or museum and has been in continuous service as a place of Christian worship since before the conquest of Istanbul. This is church of Panaghia Mouchliotissa (Παναγία Μουχλιώτισσα), a.k.a. Meryem Ana Greek Orthodox Church, a.k.a. Kanlı Kilesesi (Bloody Church), a.k.a. Church of St. Mary of the Mongols. Since it is far less known than St. George Church of the Ecumenical Patriarchate or St. Stephen of the Bulgars, the only cast-iron church in the East Orthodox world, I’ll start with telling you its amazing history.