- One of the five leaders of the Pentarchy, the highest-ranking bishops in the Christian Church prior to the Great Schism, who were the bishops of Rome, Constantinople, Alexandria, Antioch, and Jerusalem; or
- One of the nine leading bishops of the Eastern Orthodox Church in the present day, including the patriarchs of Constantinople, Alexandria, Antioch and Jerusalem mentioned above, and also the five more recently established patriarchs of (in chronological order of establishment) Bulgaria, Georgia, Serbia, Moscow and Romania; or
- One of ten high-ranking bishops of the Roman Catholic Church: seven "patriarchs of the east" (six who are heads of Eastern Catholic Churches and the Latin Patriarch of Jerusalem), plus the patriarchs of Lisbon, Venice and the East Indies; or
- One of the several leading bishops holding the title of patriarch in Oriental Orthodoxy and the Church of the East.
The five patriarchs of the Pentarchy sat in Rome, Constantinople (now Istanbul), Alexandria, Antioch, and Jerusalem. The East-West Schism of 1054 split the Latin-speaking see of Rome from the four Greek-speaking patriarchates, forming distinct Roman Catholic and Eastern Orthodox Churches. The Eastern Orthodox Patriarch of Antioch moved to Damascus in the 13th century, during the reign of the Egyptian Mamelukes, conquerors of Syria. In Damascus a Christian community had flourished since apostolic times (Acts 9). However, the patriarchate is still called the Patriarchate of Antioch. Damascus is the seat also of the Syrian Catholic and the Melkite Catholic Patriarchs of Antioch, while the Maronite Catholic of Antioch lives in Bkerké, Lebanon.
The four early Orthodox (Greek) patriarchates of the East, Constantinople, Alexandria, Antioch and Jerusalem, along with their Latin Catholic counterpart in the West, Rome, are distinguished as "senior" (Greek: πρεσβυγενή, presbygenē, "senior-born") or "ancient" (παλαίφατα, palaíphata, "of ancient fame") and are among the apostolic sees, having had one of the Apostles or Evangelists as their first bishop: Andrew, Mark, Peter, James, and Peter again, respectively.
In the Roman Catholic Church, some patriarchal titles are purely honorary, without an actual residential see, and hence termed Titular Patriarch(ate)s, either vested in another (residential) patriarchal see or in the Pope's gift.
A patriarchate has "legal personality" in some legal jurisdictions, that means it is treated as a corporation. For example, the Orthodox Patriarchate of Jerusalem filed a lawsuit in New York, decided in 1999, against Christie's Auction House, disputing the ownership of the Archimedes Palimpsest.
The head of the Czechoslovak Hussite Church is also called a Patriarch.
- Annuario Pontificio 2012, pp. 3-8. The title of "Patriarch of the West" for the Pope is no longer in use.
- In his motu proprio [http://www.vatican.va/holy_father/paul_vi/motu_proprio/documents/hf_p-vi_motu-proprio_19650211_ad-purpuratorum_lt.html Ad Purpuratorum Patrum of 11 February 1965, Pope Paul VI decreed that Eastern Catholic Patriarchs who became cardinals would be ranked as Cardinal Bishops, not Cardinal Priests, as had previously been the case, and that they would yield precedence only to the six Cardinal Bishops who hold the titles of the suburbicarian sees.
- Annuario Pontificio 2012, pp. 3-5
- Herbermann, Charles, ed. (1913). "Patriarch and Patriarchate". Catholic Encyclopedia. New York: Robert Appleton Company.