By definition, a bishop is an "overseer" of a community of the faithful, so when a priest is ordained a bishop, the tradition of the Catholic, Eastern Orthodox and Oriental Orthodox churches is that he be ordained for a specific place.
At the same time, the office of titular bishop memorializes ancient Churches, most of which were suppressed because they fell into the hands of non-Christian conquerors.
[citation needed] Beginning in 2019, titular sees are no longer being assigned to new Vicars Apostolic.
[citation needed] When Francis Green[2] was named Coadjutor Bishop of Tucson, Arizona, in 1960, his official title remained "Titular Bishop of Serra" until he succeeded Daniel James Gercke later that same year.
For instance, in 1995, Jacques Gaillot, known for his activism on Catholic-sensitive social and political topics (such as support for contraception and abortion), was transferred from the see of Évreux in France to Partenia, a titular see in Algeria, instead of becoming Bishop Emeritus of Évreux.
In Ecumenical Patriarchate of Constantinople, titular bishops and metropolitans are usually appointed with titles of former dioceses in the regions of Thrace, Asia Minor and Pontus (now Turkey), that were often active until the Greek-Turkish population exchange of 1923.