The term exarch comes from the Ancient Greek ?, exarchos, and designates holders of various historical offices, some of them being political or military and others being ecclesiastical.
In the late Roman Empire and early Byzantine Empire, an exarch was a governor of a particular territory. From the end of the 3rd century or early 4th, every Roman diocese was governed by a vicarius, who was titled "exarch" in eastern parts of the Empire, where the Greek language and the use of Greek terminology dominated, even though Latin was the language of the imperial administration from the provincial level up until the 440s (Greek translations were sent out with the official Latin text). In Greek texts, the Latin title is spelled (bikarios). The office of exarch as a governor with extended political and military authority was later created in the Byzantine Empire, with jurisdiction over a particular territory, usually a frontier region at some distance from the capital Constantinople.
In the Eastern Christian Churches (Eastern Orthodox, Oriental Orthodox and Eastern Catholic), the term exarch has three distinct uses: a metropolitan who holds the office of exarch is the deputy of a patriarch and holds authority over bishops of the designated ecclesiastical region (thus, a position between that of patriarch and regular metropolitan); or an auxiliary or titular bishop appointed to be exarch over a group of the faithful not yet large enough or organized enough to be constituted an eparchy or diocese (thus the equivalent of a vicar apostolic); or a priest or deacon who is appointed by a bishop as his executive representative in various fields of diocesan administration (in the Byzantine Empire, executive exarchs were usually collecting diocesan revenues for local bishops).
In the civil administration of the Byzantine Empire the exarch was, as stated above, the imperial governor of a large and important region of the Empire. The Exarchates were a response to weakening imperial authority in the provinces and were part of the overall process of unification of civil and military offices, initiated in early form by Justinian I, which would lead eventually to the creation of the Thematic system by either the Emperor Heraclius or Constans II.
After the dissolution of the Western Empire in the late fifth century, the Eastern Roman Empire remained stable through the beginning of the Middle Ages and retained the ability for future expansion. Justinian I reconquered North Africa, Italy, Dalmatia and finally parts of Spain for the Eastern Roman Empire. However, this put an incredible strain on the Empire's limited resources. Subsequent emperors would not surrender the re-conquered land to remedy the situation. Thus the stage was set for Emperor Maurice to establish the Exarchates to deal with the constantly evolving situation of the provinces.
In Italy the Lombards were the main opposition to Byzantine power. In North Africa the Amazigh or Berber princes were ascendant due to Roman weakness outside the coastal cities. The problems associated with many enemies on various fronts (the Visigoths in Spain, the Slavs and Avars in the Balkans, the Sassanid Persians in the Middle East, and the Amazigh in North Africa) forced the imperial government to decentralize and devolve power to the former provinces.
The term Exarch most commonly refers to the Exarch of Italy, who governed the area of Italy and Dalmatia, still remaining under Byzantine control after the Lombard invasion of 568. The exarchate's seat was at Ravenna, whence it is known as the "Exarchate of Ravenna". Ravenna remained the seat of the Exarch until the revolt of 727 over Iconoclasm. Thereafter, the growing menace of the Lombards and the split between eastern and western Christendom that Iconoclasm caused made the position of the Exarch more and more untenable. The last Exarch was killed by the Lombards in 751.
A second exarchate was created by Maurice to administer northern Africa, formerly a separate praetorian prefecture, the islands of the western Mediterranean and the Byzantine possessions in Spain. The capital of the Exarchate of Africa was Carthage. An emperor of the Eastern Roman Empire, Heraclius, was the son of the exarch of Africa before Heraclius replaced the usurper emperor Phocas in 610. Phocas had revolted under emperor Maurice who had appointed Heraclius' father as exarch of Africa. The exarchate proved both financially and militarily strong, and survived until the Arab Muslim conquest of Carthage in 698.
The term exarch entered ecclesiastical language at first for a metropolitan (an archbishop) with jurisdiction not only for the area that was his as a metropolitan, but also over other metropolitans within local political dioceses. Since imperial vicarius (governor of a political diocese) was often called "exarch" in eastern, Greek speaking parts of the Empire, it became customary for the metropolitans of the diocesan capitals (Ephesus in the Diocese of Asia, Heraclea in the Diocese of Thrace and Caesarea in the Diocese of Pontus) also to use the title "exarch" in order to emphasize their precedence and primatial status over other metropolitans within local political dioceses.
The Council of Chalcedon (451), which gave special authority to the see of Constantinople as being "the residence of the emperor and the Senate," in its canons spoke of diocesan "exarchs", placing all metropolitans in dioceses of Asia, Thrace and Pontus (including metropolitans-exarchs of Ephesus, Heraclea and Caesarea) under the jurisdiction of the Archbishop of Constantinople. Metropolitans-exarchs of Ephesus tried to resist the supreme jurisdiction of Constantinople, but eventually failed since imperial government supported the creation of a centralized Patriarchate.
When the proposed government of universal Christendom by five patriarchal sees (Rome, Constantinople, Alexandria, Antioch and Jerusalem, known as the pentarchy), under the auspices of a single universal empire, was formulated in the legislation of Emperor Justinian I (527-565), especially in his Novella 131, and received formal ecclesiastical sanction at the Council in Trullo (692), the name "patriarch" became the official one for the heads of major autocephalous churches, and the title of "exarch" was further demoted by naming all metropolitans as "patriarchal exarchs" in their ecclesiastical provinces. The advance of Constantinople put an end to privileges of three older, original exarchates, which fell back to the state of ordinary metropolitan sees.
Local ecclesiastical development in some regions also included the title of exarch. Since the Church of Cyprus was declared autocephalous (431), its Primate received the title of Exarch of Cyprus. On the similar principle the Archbishop of Mount Sinai and Raithu is an exarch, though in this case, as in that of Cyprus, modern Eastern Orthodox usage generally prefers the title "Archbishop".
In modern ecclesiastical practice of the Eastern Orthodox Church, the title of exarch was often used to designate the highest hierarchical office under the rank of patriarch. When Russian Patriarch Adrian of Moscow died in 1700, Emperor Peter the Great abolished the patriarchal office and appointed Metropolitan Stefan Yavorsky as "exarch" and head of the governing council of the Russian Orthodox Church.
After imperial Russia annexed Georgia (eastern part in 1801, and western part in 1810), the ancient Georgian Orthodox Church (autocephalous since 750, whose head was since 1008 styled Catholicos-Patriarchs) was reorganized into Georgian Exarchate, and the newly appointed Exarch of Georgia (since 1817 always an ethnic Russian) sat in the Russian Holy Synod at St. Petersburg. Since the entire region of Caucasus fell under the Russian rule, jurisdiction of Georgian Exarchate was expanded, encompassing territories of modern-day Georgia, Armenia and Azerbaijan. On 7 April 1917, the Georgian Patriarchate was restored for the Archbishops of Mtsheta and Tbilisi, with the style Catholicos-Patriarch of All Georgia, and the title Exarch of Georgia was extinguished, but only for the Georgian part of the Exarchate. The Russian Orthodox Church and its exarch Platon (Rozhdestvensky) kept their jurisdiction over non-Georgian parts of the Caucasian region, and for those territories Caucasian Exarchate of the Russian Orthodox Church was created in the summer of 1917, with metropolitan Platon as Exarch of Caucasus. In the spring of 1918, he was succeeded by metropolitan Cyril (Smirnov) as new Exarch of Caucasus, but after his transfer to another post in the spring of 1920 no new exarch was appointed.
On 28 February 1870 the twenty-year-old struggle between Greeks and Bulgarians for the control of the Orthodox Church in Bulgaria culminated when the Ottoman Sultan Abd-ul-Aziz created an independent Bulgarian ecclesiastical organization, known as the Bulgarian Exarchate. The Orthodox Church in Bulgaria had now become independent of the Greek-dominated Ecumenical Patriarchate of Constantinople. The Bulgarian Exarch, who resided in Constantinople, became the most famous bearer of the title of exarch; his adherents throughout region were called exarchists, as opposed to the Greek patriarchists. The ensuing struggle, waged especially in Macedonia, was not only religious but had a conspicuous political dimension of a contention between competing Greek and Bulgarian national aims. For more information see Bulgarian Exarchate and Bulgarian Orthodox Church.
In 1921, eparchies of the Russian Orthodox Church in Ukraine were reorganized as Ukrainian Exarchate of the Russian Orthodox Church, headed by patriarchal exarch with seat in Kiev. The Ukrainian Exarchate existed until 1990 when it was granted a higher degree of ecclesiastical autonomy within the Moscow Patriarchate. In 1989, an autonomous Belarusian Exarchate of the Russian Orthodox Church was formed, with jurisdiction over eparchies in Belarus.
During the 20th century, the pentarchy-number principle, already abandoned in the case of Bulgaria (10th century), Serbia (14th century) and Russia (16th century), gave way to the desire of the now politically independent orthodox nations to see their sovereignty reflected in ecclesiastical autonomy - autocephaly - and the symbolic title to crown it: a 'national' Patriarch. For example, Bulgarian Exarchate was raised to the rank of Patriarchate in 1953.
In the Eastern Orthodox Church, the office of exarch can be also given to a special deputy of a Patriarch, with jurisdiction over a community outside the home territory of the Patriarchate. Thus, in the United States there are Exarchs representing, among others, the Serbian, Romanian, Bulgarian and Jerusalem Patriarchs. The style of the Exarchs of the Patriarchate of Jerusalem is "Exarch of the Holy Sepulcher".
The Mexican Orthodox parishes in five deaneries (Mexico City, D.F., State of Mexico, State of Jalisco, State of Veracruz and State of Chiapas) of the Orthodox Church in America are governed as the "Exarchate of Mexico", currently under the leadership of Bishop Alejo of Mexico City.
The Oriental Orthodox Patriarch of Antioch currently has under his authority an Exarch in India, known by the ancient title Maphrian, although he is popularly referred to as Catholicos. This is not to be confused with the autocephalous Catholicate of the East, which is also located in India.
Historically, there have been a very few cases of the civil title of Exarch granted by the civil authority to prelates of the Latin Church, as when Emperor Frederick I named the Archbishop of Lyon Exarch of Burgundy in 1157.
However, the ecclesiastical title of Exarch has disappeared in the Western Catholic Church, being replaced by the terms "Primate" (ranking above Metropolitan Archbishop) and "Apostolic Vicar" (ranking below Suffragan Bishop).
In Eastern Catholic Churches (of Eastern tradition but in full communion with the Bishop of Rome, the Pope), the ecclesiastical title of Exarch is in common use, just as with its Orthodox counterparts.
These Churches are, in general, not identified with a particular liturgical rite. Thus, no less than fourteen of them use the one same Byzantine Rite, mostly in one or other of only two languages, Greek and Church Slavonic, but they maintain their distinct identities. Because of population shifts, half or so of these Churches have not just exarchates but full-scale eparchies (bishoprics) or even archeparchies (archdioceses) outside their original territory.
Apostolic exarch is usually a consecrated bishop of a titular see to whom the Pope, as Bishop of the Roman See of the Apostle Peter, has entrusted the pastoral care of the faithful of an autonomous Eastern Catholic particular Church sui iuris in an area, not raised to the rank of eparchy (diocese), that is situated outside the home territory of an Eastern Catholic Church. The office of apostolic exarch thus corresponds to what in the Latin Church is called an Apostolic vicar. Apostolic exarchates are generally exempt (immediately subject to the Holy See), with limited oversight by the Patriarch, Major Archbishop or Metropolitan in chief of the particular Eastern Church. It there is no metropolitan in a particular Eastern Catholic church, apostolic exarchates in their territories are directly subjected to Rome. For example, Byzantine Catholic Apostolic Exarchate of Serbia belongs to the Byzantine Catholic Church of Croatia and Serbia, but since there is no metropolitan in that church, Apostolic Exarch of Serbia is directly subjected to the Holy See.
Patriarchal exarch is appointed in those Eastern Catholic churches whose head is styled as patriarch. Office of patriarchal exarch is often (not always) given to a consecrated bishop of a titular see. Their appointments are limited to the traditional territory of their church, with main task of governing the region not yet raised to the rank of eparchy (diocese). They may be suffragan to an archdiocese or archeparchy of the Eastern Catholic Church, or be immediately subject to the Patriarch.
Archiepiscopal exarch is appointed in those Eastern Catholic churches whose head is styled as Major Archbishop. Office of archiepiscopal exarch is also usually given to a consecrated bishop of a titular see. Appointment of archiepiscopal exarchs is limited to the traditional territory of their particular church. They also may be suffragans to an archdiocese or archeparchy of their Eastern Catholic Church, or be immediately subject to the Major Archbishop.
In particular cases, usually because of illness or some other problem, an exarch of any rank can be assisted by the appointment of a colleague who is called Coadjutor exarch. The position of coadjutor exarch towards his superior exarch is similar to the position of Latin coadjutor bishop towards his superior diocesan bishop. Coadjutor exarchs are appointed with rights of succession. For example, in 1993 titular Bishop Christo Proykov of Briula was appointed Coadjutor to Apostolic Exarch of Sofia, Methodius Stratiev, and when the latter died in 1995 coadjutor exarch succeeded him as the new Apostolic Exarch.
In practice, exarch of any rank can be additionally assisted by an auxiliary exarch, who is appointed in order to help the exarch in administration of his exarchate. Position of auxiliary exarch towards his superior exarch is similar to position of Latin auxiliary bishop towards his superior diocesan bishop. Auxiliary exarchs are appointed without the rights of succession.
The following Eastern Catholic exarchates can be found in the 2006 Annuario Pontificio and newer sources. The Apostolic Exarchates are exempt, i.e. immediately subject to the Holy See, rather than to their Patriarch or other head of the particular Church
(probably still incomplete)