St. George's Cathedral, Istanbul

The Ecumenical Patriarchate of Constantinople (Greek: Οἰκουμενικὸν Πατριαρχεῖον Κωνσταντινουπόλεως, romanized: Oikoumenikón Patriarkhíon Konstantinoupóleos, IPA: [ikumeniˈkon patriarˈçion konstandinuˈpoleos]; Latin: Patriarchatus Oecumenicus Constantinopolitanus; Turkish: Rum Ortodoks Patrikhanesi, İstanbul Ekümenik Patrikhanesi, "Roman Orthodox Patriarchate, Ecumenical Patriarchate") is one of the fourteen to sixteen autocephalous churches (or "jurisdictions") that together compose the Eastern Orthodox Church. It is headed by the Ecumenical Patriarch of Constantinople, currently Bartholomew I, Archbishop of Constantinople. Because of its historical location as the capital of the former Eastern Roman (Byzantine) Empire and its role as the mother church of most modern Orthodox churches, Constantinople holds a special place of honor within Orthodoxy and serves as the seat for the Ecumenical Patriarch, who enjoys the status of primus inter pares (first among equals) among the world's Eastern Orthodox prelates and is regarded as the representative and spiritual leader of Eastern Orthodox Christians.The Ecumenical Patriarchate promotes the expansion of the Christian faith and Eastern Orthodox doctrine, and the Ecumenical Patriarchs are involved in ecumenism and interfaith dialogue, charitable work, and the defense of Orthodox Christian traditions. Prominent issues for the Ecumenical Patriarchate's policy in the 21st century include the safety of the believers in the Middle East, reconciliation of the Eastern Orthodox and Catholic churches, and the reopening of the Theological School of Halki, which was closed down by the Turkish authorities in 1971.

Fener (Turkish pronunciation: [feˈnæɾ]; historically in Greek: Φανάρι, Phanári; in English also: Phanar) is a quarter midway up the Golden Horn within the district of Fatih in Istanbul, Turkey. The streets in the area are full of historic wooden mansions, churches, and synagogues dating from the Byzantine and Ottoman eras. The wooden mansions between the main axis and the shore were often used for importing wood from Pontus or the Black Sea area. Their picturesque facades were largely destroyed due to street widening requirements in the 1930s and later. The area's name is a Turkish transliteration of the original word "fanarion" (Medieval Greek: Φανάριον) (a lighting lantern, a streetlight, a lightpost with a light lantern). It was so called for a column topped with a lantern which stood there in the Byzantine period – used as a public light or marine and/or other purpose locator/beacon. After the Fall of Constantinople in 1453, the Fener district became home to many of the Greeks in the city. The Patriarchate of Constantinople moved to the area as well and is still located there. As a result, "Phanar(i)" (the traditional spelling) is often used as shorthand for the Ecumenical Patriarchate, just as "Vatican" is used for the Holy See of the Roman Catholic Church. During the Ottoman period, the Greek inhabitants of Fener were called "Phanariotes" and were important assistants to the Sultan in various capacities and offices. Wealthy Phanariotes were appointed as governors over provinces in Turkish Europe and Greece, and as hospodars of Wallachia and Moldavia between 1711 and 1821. The Phanar contains the patriarchal cathedral of St. George. Its main entrance is never opened since the then Patriarch was hanged there in 1821, at the time of Greek independence. The oldest surviving Greek school in Istanbul, Özel Fener Rum Lisesi, is found in Fener. The school was established in 1454. An important Bulgarian church, St. Stephen ("The Iron Church"), lies between the patriarchate and the shore of the Golden Horn. There are a number of other barely used Greek Orthodox churches.

The 557 Constantinople earthquake took place on the night of December 14. This earthquake, described in the works of Agathias, John Malalas, and Theophanes the Confessor, caused great damage to Constantinople, then capital of the Byzantine Empire in a region frequently afflicted with earthquakes. More minor quakes had preceded the large event, including two in April and October respectively. The main quake in December was of unparalleled ferocity, and "almost completely razed" the city. It caused damage to the Hagia Sophia which contributed to the collapse of its dome the next year, as well as damaging the walls of Constantinople to the extent that Hun invaders were able to penetrate it with ease the following season.

The Yavuz Selim Mosque, also known as the Selim I Mosque and the Yavuz Sultan Selim Mosque (Turkish: Yavuz Selim Camii) is a 16th-century Ottoman imperial mosque located at the top of the 5th Hill of Istanbul, Turkey, in the neighborhood of Çukurbostan, overlooking the Golden Horn. Its size and geographic position make it a familiar landmark on the Istanbul skyline.

Phanar Greek Orthodox College or Phanar Roman Orthodox Lyceum (Turkish: Özel Fener Rum Lisesi), known in Greek as the Great School of the Nation (Greek: Μεγάλη του Γένους Σχολή, Megáli toú Genous Scholí), is the oldest surviving and most prestigious Greek Orthodox school in Istanbul, Turkey. The school, like all minority schools in Turkey, is a secular school.

Saint Mary of the Mongols (full name in Greek: Θεοτόκος Παναγιώτισσα (pr. Theotókos Panaghiótissa, lit. "All-Holy Theotokos") or Παναγία Μουχλιώτισσα (pr. Panaghía Muchliótissa); Turkish name: Kanlı Kilise (meaning: Bloody Church), is an Eastern Orthodox church in Istanbul. It is the only remaining Byzantine church of Constantinople that has never been converted to a mosque, always remaining open to the Greek Orthodox Church.

Bulgarian St Stephen Church (Bulgarian: Църква "Свети Стефан"; Turkish: Sveti Stefan Kilisesi), also known as the Bulgarian Iron Church, is a Bulgarian Orthodox church in Balat, Istanbul, Turkey. It is famous for being made of prefabricated cast iron elements in the neo-Byzantine style. The church belongs to the Bulgarian minority in the city.

Fındıkzade is a quarter in the European side of Istanbul, located in the north side of Fatih, the province's capital district (the walled city), lying between the quarters of Topkapı and Aksaray, and adjacent to the Hasseki, Yusufpaşa and Çapa quarters. The main roads of this quarter are Millet Caddesi (now called Turgut Özal Millet Caddesi) and Vatan Caddesi (now called Adnan Menderes Vatan Caddesi). Three of the major city's hospitals are located here, making of it one of the most important health district in Istanbul.

Çukurbostan is a quarter of the European side of Istanbul located in the north side of the Fatih district (the walled city). Although it is difficult to define exactly its boundary, Çukurbostan lies between the neighbourhoods of Balat and Atikali. In the quarter are located the Yavuz Selim Mosque and the Byzantine Cistern of Aspar. The cistern was used in the Ottoman period as a vegetable garden, and its name Çukurbostan ("sunken garden") gave the name to the quarter.

The Cistern of Aspar (Greek: ἡ τοῦ Ἂσπαρος κινστέρνη) or Great Cistern (Greek: μεγίστη κινστέρνη), known in Turkish as Sultan Selim Çukurbostanı ("sunken garden of Sultan Selim"), was a Byzantine open-air water reservoir in the city of Constantinople.

The Cistern of Pulcheria (Greek: Κινστέρνα Πουλχερίας, Turkish: Pulcheria Sarnıcı) is a Byzantine period covered cistern built in Constantinople (modern Istanbul, Turkey).

Gül Mosque (Turkish: Gül Camii, meaning: "The Mosque of the Rose" in English) is a former Eastern Orthodox church in Istanbul, Turkey, converted into a mosque by the Ottomans.