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).