The Ecumenical Patriarch is the Archbishop of Constantinople

Constantinople

Constantinople was the capital of the Roman, Eastern Roman, Byzantine, Latin, and Ottoman Empires. Throughout most of the Middle Ages, Constantinople was Europe's largest and wealthiest city.-Names:...

 – New Rome – ranking as primus inter pares

Primus inter pares

Primus inter pares is Latin phrase describing the most senior person of a group sharing the same rank or office.When not used in reference to a specific title, it may indicate that the person so described is formally equal, but looked upon as an authority of special importance by their peers...

(first among equals) in the Eastern Orthodox communion

Eastern Orthodox Church organization

This article covers the organization of the Eastern Orthodox Churches rather than the doctrines, traditions, practices, or other aspects of Eastern Orthodoxy...

, which is seen by followers as the One, Holy, Catholic, and Apostolic Church.

The Ecumenical Patriarch has been historically known as the Greek

Greek Orthodox Church

The Greek Orthodox Church is the body of several churches within the larger communion of Eastern Orthodox Christianity sharing a common cultural tradition whose liturgy is also traditionally conducted in Koine Greek, the original language of the New Testament...

 Patriarch of Constantinople, as distinct from the Armenian Patriarch of Constantinople

Armenian Patriarch of Constantinople

The Armenian Patriarch of Constantinople also known as Armenian Patriarch of Istanbul is today head of The Armenian Patriarchate of Constantinople , one of the smallest Patriarchates of the Oriental Orthodox Church but one that has exerted a very significant political role and today still exercises...

 and the ancient Latin Patriarch of Constantinople

Latin Patriarch of Constantinople

The Latin Patriarch of Constantinople was an office established as a result of Crusader activity in the Near East. The title should not be confused with that of the Patriarch of Constantinople, an office which existed before and after....

. Historically, within the five ecumenical sees of Pentarchy

Pentarchy

Pentarchy is a term in the history of Christianity for the idea of universal rule over all Christendom by the heads of five major episcopal sees, or patriarchates, of the Roman Empire: Rome, Constantinople, Alexandria, Antioch, and Jerusalem...

, the patriarch is regarded as the successor of Saint Andrew

Saint Andrew

Saint Andrew , called in the Orthodox tradition Prōtoklētos, or the First-called, is a Christian Apostle and the brother of Saint Peter. The name "Andrew" , like other Greek names, appears to have been common among the Jews from the 3rd or 2nd century BC. No Hebrew or Aramaic name is recorded for him...

, the Apostle.