The Vefa Kilise Mosque, located on the back of Istanbul’s third hill, was built between the 10th and 11th centuries. After the invasion of the city by Latin Cruders, the church was restored  and used as a RomanCatholic Church. After the conquest of İstanbul, the church was converted into  a mosque by Molla Gürani. It was destroyed by fire in 1883. The mosaics discovered  her during restoration work in 1937 are now considered to be among the most important of such Works in the city today.