The '''Church of Panagia Blachernae''' (full name in Greek: ''Θεοτòκος τών Βλαχερνών'' (pr. Theotókos tón Blachernón); Turkish name: ''Meryem Ana Kilisesi'') is located in Istanbul, in the district of Fatih, in the neighbourhood of Ayvansaray, along ''Mustafa Paşa Bostanı Sokak''. It lies a few hundred meters inside the walled city, at a short distance from the shore of the Golden Horn. The building is protected by a high wall, and preceded by a garden.
The church is near the northern tip of the walls of
Theodosios built by the Empress [[Pulcheria the Empress|Pulcheria]] (ca. 450-453), and her husband, Emperor [[Marcian]] (450-457). They had the church built on the site of a sacred spring, which was a place of [[pilgrim]]age near the shore of the Golden Horn (known as ''Ayvansaray'' today). Inside is now the best known and most celebrated [http://www.ec-patr.org/afieroma/churches/show.php?lang=en&id=02 sanctuary to the Virgin Mary in Constantinople]. Emperor Leo I (457-474) completed the church by adding the [[Life-giving Fount of the Theotokos|"Hagiasma"]] <ref> the '''''Hagiasma''''' in this case, is the fountain of holy water where water flowed out of the hands of the marble statue of the Virgin Mary </ref>. <ref>[http://www.uni-heidelberg.de/subject/hd/fak7/hist/o1/logs/byzans-l/log.started941201/mail-21.html ''Oxford Dictionary of Byzantium''] (ODB) 1:293; Janin, Eglises CP, 161-71 and the end map entitled "Byzance Constantinople," ref. D2; George P. Majeska, Russian Travelers to Constantinople in the Fourteenth and Fifteenth Centuries, (Washington, D.C.: 1984), 333-337.</ref>He also built the "Hagion Lousma" <ref> the Hagion Lousma was a sacred pool where the emperors would participate in a bathing purification ritual</ref>.
Emperor Leo I also built the circular pareklision ''Hagia Soros'' ([[chapel]]), next to the church to contain the holy [[Protection of the Mother of God|robe]] and girdle of the Virgin Mary, brought from Palestine in 458 (or 473). The chapel of the Virgin's robe was covered in silver and considered a "reliquary of architectural dimensions." Lay people were not allowed inside but could pray in the main church.<ref>[http://www.uni-heidelberg.de/subject/hd/fak7/hist/o1/logs/byzans-l/log.started941201/mail-21.html ''ODB''] 3:1929.</ref> This very shrine housed the miracle-working icon of the '''''Blachernitissa'''''.
In 625-626, Constantinople was attacked by the Avards. Emperor Heraclius (575-641) campaigned against the Persians, however, the icon was carried in a procession along the city walls and so the saving of the city was attributed to the intervention of the Theotokos. In order to protect the sanctuary, and the city from such a siege, Leo I added the famous quarter of Blachernae in 627, with its venerated church, whose image was now considered the palladium of Constantinople. The circumference of the walls were then, and still are, eleven to twelve miles. By this stage, the church of Blachernae had around 75 endowed [[clergy|clerics]].
During the iconoclastic period, and according to tradition, the icon disappeared and was then found hidden behind a wall during renovation works in 1030.
* the ''Eastern Council of Blachernae'' (Constantinople) in 1285. At this council, a significant statement was produced addressing the theological issue of the 'Filioque'. Despite the concern of Byzantine theologians to oppose the idea of the Filioque and its addition to the creed, there is no reference to it in the '''''Synodikon of Orthodoxy''''' <ref> a collection containing more than sixty anathemas representing the doctrinal decisions of Eastern councils through the fourteenth century.</ref>;
* the original icon of [[Theotokos of Tikhvin|Tikhvin]] ([[Panagia Hodegetria|Hodegetria]]), painted by the Holy [[Apostle Luke]] and kept in the Church of Blachernae for about five hundred years. It was sent to Russia in 1383, before the fall of Constantinople. It is said that fishermen saw it surrounded in lights over the Lake of Ladoga in Russia. The icon was later found on the bank of the Tikhvin River and was placed in the local church. Recently, the icon was kept in Chicago and returned to Russia.
* [[District of the Phanar and the Keratius gulf]] part of the [[Church of Constantinople]], within the geographical area of Istanbul.
* [[Panagia Blachernitissa]] icon