In Çember Sokak in the neighbourhood of Ayvansaray, in the district of Fatih, Istanbul, it lies just inside the walled city at a short distance from the Golden Horn, at the foot of the sixth hill of Constantinople.

[1] Stylistically, it belongs to the eleventh or twelfth century.Towards the middle of the ninth century, Princess Thekla, the eldest daughter of Emperor Theophilus enlarged a small oratory, dedicated to her patron saint and namesake, lying 150 metres (490 feet) east of the Church of Theotokos of the Blachernae.

[4] Shortly after that, Kapicibaşi[5] (and later Grand Vizier) Koca Mustafa Pasha[6] repaired the damage and converted the church into a mosque.

[7] Up to the end of the nineteenth century, a hamam, 150 metres (490 feet) south of the building, formed part of the mosque's foundation.

[2] Inside the apse of the building is a türbe (tomb) attributed to Hazreti Cabir (Jabir) Ibn Abdallah-ül-Ensamı, one of the companions of Eyüp,[8] who fell nearby in 678 during the first Arab siege of Constantinople.

The dome piers, which form the internal side of the cross, are L-shaped in an example of the stage preceding that of the cross-in-square church with four columns.