Kasım Ağa Mosque with the minaret of Odalar Mosque in the background
Odalar Mosque was situated in the northwestern part of Constantinople, a short distance from the Monastery of Chora and the Cistern of Aetius. It is possible that Odalar Mosque, along with the nearby Kasım Ağa Mosque and the Ipek Cistern, once formed part of a monastery. Today the building has almost disappeared and its few remains incorporated in the courtyards of adjacent houses.
Odalar Mosque has two distinct construction phases, one perhaps from the 10th century and another from the 12th century. Only the tripartite east end of the original church could be reconstructed. The side rooms, slightly asymmetrical, projected beyond the central apse. It also consisted of crypt (around 2 x 4 meters) under the central apse. In the middle of the twelfth century, the older building was reconfigured to function as the substructure for the new cross-in-square church on the upper level. There is evidence that Odalar had outer aisles. The south room of the tripartite sanctuary was larger than the north. It was probably capped with dome and was decorated with a Marian cycle, suggesting that a separate chapel rather than a diakonikon. The apse of the north crypt chamber was once decorated with a fresco of the Theotokos and Christ child flanked by two angels. It seems that the nearby Kasım Ağa Mosque, dating to the Palaiologan era, was not a church, but rather a utilitarian building, possibly associated with Odalar Mosque.
It was given to Christians from the Genoese colony of Caffa (Turkish Kefe, Greek Theodosia) in the Crimea after its conquest in 1475. The district (which also included the nearby Church of St. Nicholas, later known as Kefeli Mosque) remained in Christian hands until the mid-seventeenth century. In 1640, it was converted into a mosque by the Vizier Kemankeş Kara Mustafa Pasha, after whom the mosque was originally named. Later it received its present name Odalar ("chambers") Mosque, referencing its multiple chambers. The building was severely damaged by a fire in 1919. It largely disappeared under residential buildings in the 1950s. These buildings were recently demolished.
Fresco of St. Mercurius of Caesarea
Late 13th-early 14th century
Istanbul Archaeological Museums
Plan by Brunov
Plan by Muller-Wiener
Architecture and Ritual in the Churches of Constantinople Ninth to Fifteenth Centuries by Vasileios Marinis
Converted Byzantine Churches in Istanbul: Their Transformation Into Mosques and Masjids by S. Kirimtayif
Bildlexikon zur Topographie Istanbuls: Byzantion, Konstantinupolis, Istanbul by Wolfgang Müller-Wiener