Patriarchate of Constantinople in the context of "Pentarchy"

Mehmed II (Ottoman Turkish: محمد ثانى, romanized: Meḥemmed-i s̱ānī; Turkish: II. Mehmed, pronounced [icinˈdʒi ˈmehmet]; 30 March 1432 – 3 May 1481), commonly known as Mehmed the Conqueror (Ottoman Turkish: ابو الفتح, romanized: Ebū'l-fetḥ, lit. 'the Father of Conquest'; Turkish: Fâtih Sultan Mehmed), was twice the sultan of the Ottoman Empire from August 1444 to September 1446 and then later from February 1451 to May 1481.

In Mehmed II's first reign, he defeated the crusade led by John Hunyadi after the Hungarian incursions into his country broke the conditions of the truce per the Treaties of Edirne and Szeged. When Mehmed II ascended the throne again in 1451, he strengthened the Ottoman Navy and made preparations to attack Constantinople. At the age of 21, he conquered Constantinople and brought an end to the Byzantine Empire. After the conquest, Mehmed claimed the title caesar of Rome (Ottoman Turkish: قیصر روم, romanized: qayṣar-i rūm), based on the fact that Constantinople had been the seat and capital of the surviving Eastern Roman Empire since its consecration in 330 AD by Emperor Constantine I. The claim was soon recognized by the Patriarchate of Constantinople, albeit not by most European monarchs.

Çermenikë or Çermenika is an upland northeast of Elbasan, in central Albania.

In the Middle Ages, as Tzernikon or Tzernikos it was an episcopal see of the Patriarchate of Constantinople, as a suffragan see of the Archbishopric of Dyrrhachium.

The Ukrainian Orthodox Church – Kyiv Patriarchate (UOC-KP; Ukrainian: Украї́нська Правосла́вна Це́рква – Ки́ївський Патріарха́т (УПЦ-КП), romanized: Ukrainska Pravoslavna Tserkva — Kyivskyi Patriarkhat (UPTs-KP)) was an Orthodox church in Ukraine, in existence from 1992 to 2018. Its patriarchal cathedral was St Volodymyr's Cathedral in Kyiv.

After its unilateral declaration of autocephaly in 1992, the UOC-KP was not recognised by the other Eastern Orthodox churches, and was considered a "schismatic group" by the Moscow Patriarchate and Ecumenical Patriarchate. Patriarch Filaret (Denysenko) was enthroned in 1995 and excommunicated by the Russian Orthodox Church in 1997, an action not recognized by the UOC-KP synod. In 2018, the Ecumenical Patriarchate of Constantinople moved unilaterally and against canonical norms to facilitate a "unification council", in contradiction to his previous statement "recognizing the fullness of the Russian Orthodox Church's exclusive competence on this issue". The canonical Ukrainian Orthodox Church rejected these overtures, noting its universal recognition as sole canonical authority on the territory of Ukraine and the political nature of the proposed council. Constantinople ignored this, "reinstated" Filaret as a bishop and facilitated the convening of a unification council. In December 2018, the unification council of the Eastern Orthodox churches of Ukraine decided to unite the UOC-KP with the Ukrainian Autocephalous Orthodox Church (UAOC), creating the Orthodox Church of Ukraine (OCU) which was subsequently granted autocephaly by the Ecumenical Patriarch of Constantinople in January 2019.

The Metropolitanate of Gothia (also of Gothia and Caffa), also known as the Eparchy of Gothia or Metropolitanate of Doros, was a metropolitan diocese of the Patriarchate of Constantinople in the Middle Ages.

The 9th-century Metropolitanate of Doros was centered in the Crimea, but it seems to have had dioceses further afield, as far east as the Caspian coast, but they were probably short-lived, as the Khazars converted to Judaism.From the 13th century until the Ottoman conquest in 1475, the Metropolitanate of Gothia was within the Principality of Theodoro (known in Greek as Γοτθία, Gothia). In 1779, it was transferred to the Russian Orthodox Church and disestablished a few years later.

The Archbishopric of Ohrid, also known as the Bulgarian Archbishopric of Ohrid (Bulgarian: Българска Охридска архиепископия; Macedonian: Охридска архиепископија), originally called Archbishopric of Justiniana Prima and all Bulgaria (Greek: ἀρχιεπίσκοπὴ τῆς Πρώτης Ἰουστινιανῆς καὶ πάσης Βουλγαρίας), was an autocephalous Eastern Orthodox Church established following the Byzantine conquest of Bulgaria in 1018 by lowering the rank of the autocephalous Bulgarian Patriarchate due to its subjugation to the Byzantines. In 1767, the Archbishopric's autocephaly was abolished, and the Archbishopric was placed under the tutelage of the Patriarchate of Constantinople.

Patriarch Filaret (secular name Mykhailo Antonovych Denysenko Михайло Антонович Денисенко, born 23 January 1929) is a Ukrainian religious leader, currently serving as the primate and Patriarch of the Ukrainian Orthodox Church – Kyiv Patriarchate. The Orthodox Church of Ukraine, that he left in 2019, views him as the Honorary Patriarch emeritus, while the Ecumenical Patriarchate of Constantinople recognises him as former Metropolitan of Kyiv.

He was formerly the Metropolitan of Kiev and the Exarch of Ukraine in the Patriarchate of Moscow (1966–1992). After joining the Kyiv Patriarchate, he was defrocked and in 1997 excommunicated by the ROC. On 11 October 2018, the Patriarchate of Constantinople reinstated him in church communion. However, while restored to the episcopate, the Ecumenical Patriarchate never recognised him as Patriarch and views him as the former Metropolitan of Kyiv. On 15 December 2018, the Ukrainian Orthodox Church of the Kyiv Patriarchate united with the Ukrainian Autocephalous Orthodox Church and some members of the Ukrainian Orthodox Church (MP) into the Orthodox Church of Ukraine; the Ukrainian Orthodox Church of the Kyiv Patriarchate thus ceased to exist.

Pope Formosus (c. 816 – 896) was the pope and ruler of the Papal States from 6 October 891 until his death on 4 April 896. His reign as Pope was troubled, marked by interventions in power struggles over the Patriarchate of Constantinople, the Kingdom of West Francia, and the Holy Roman Empire. Because he sided with Arnulf of Carinthia against Lambert of Spoleto, Formosus's remains were exhumed and put on trial in the Cadaver Synod. Several of his immediate successors were primarily preoccupied by the controversial legacy of his pontificate.