Exarch, in Greek, ἔξαρχος, ruler, originally the title given the governor of a province called a diocese under Diocletian's division of the Eastern Prefecture (297). In the organizational development of the Church, patterned in conformity with the political divisions of the Roman Empire, bishops of such dioceses assumed in addition to the title of exarch expanded jurisdiction over those metropolitans within this political unit. In addition to those heads of sees who acquired the patriarchal title at the Council of Nicaea (325), the bishops of Ephesus, Caesarea, and Heraclea, capitals of the respective dioceses of Asia, Cappadocia and Pontus, and Thrace, functioned as exarchs. With the elevation of the See of Constantinople to a patriarchate consequent upon its becoming an imperial residence, conflict arose over the extent of the exarchs' jurisdiction. This was resolved at the Council of Chalcedon (c.9), which reduced their status to that of a metropolitan, permitting their retention of this honorary title and place in the order of precedence next after the five patriarchs. Although mentioned as late as the Council of 680, the office of exarch gradually diminished in importance in the Church's reorganization, being replaced in the West by an apostolic vicar and later primate; in the East it still retained its traditional place. Autocephalous churches, especially those of Cyprus, Ipek, Ochrida, and Trnovo, emphasizing their autonomy, used this title—at times even daring to usurp that of patriarch. In 1870 at the reconstitution of the Bulgarian Orthodox Church, its head, residing in Constantinople, took the title of exarch. Oriental Patriarchs on occasion appoint exarchs with sub-ordinate bishops for semi-independent groups of their jurisdiction throughout the world. The present usage of the term exarch denoting an emissary explains the reason for its being applied even to a minor prelate assigned to a particular mission. Traditionally, Eastern Catholic canonical tradition recognized three kinds of exarchs: (1) those with a territory of their own; (2) apostolic exarchs; and (3) patriarchal or archiepiscopal exarchs who govern a territory not yet constituting a canonically erected diocese.
See Also: exarchy.
Bibliography: j. faris, The Eastern Catholic Churches: Constitution and Governance according to the Code of Canons of the Eastern Churches (Brooklyn 1993). v. pospishil, Eastern Catholic Church Law (Brooklyn, NY 1996).
"Exarch." New Catholic Encyclopedia. . Encyclopedia.com. (February 15, 2019). https://www.encyclopedia.com/religion/encyclopedias-almanacs-transcripts-and-maps/exarch
"Exarch." New Catholic Encyclopedia. . Retrieved February 15, 2019 from Encyclopedia.com: https://www.encyclopedia.com/religion/encyclopedias-almanacs-transcripts-and-maps/exarch