A titular bishop in various churches is a bishop who is not in charge of a diocese. 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. There are more bishops than there are functioning dioceses. Therefore, a priest appointed not to head a diocese as its diocesan bishop but to be an auxiliary bishop, a papal diplomat, or an official of the Roman Curia is appointed to a titular see. Catholic Church In the Catholic Church, a titular bishop is a bishop who is not in charge of a diocese. Examples of bishops belonging to this category are coadjutor bishops, auxiliary bishops, bishops emeriti, vicars apostolic, nuncios, superiors of departments in the Roman Curia, and cardinal bishops of suburbicarian dioceses (since they are not in charge of the suburbicarian dioceses). Most titular bishops hold the title to a titular see. Assigning titular sees serves two purposes. Since part of being a bishop means being the head of a Christian church, titular sees serve that purpose for bishops without a diocese. 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. For this reason the former terminology was not "titular bishop" but "bishop in infidel regions" (in partibus infidelium). In recent times the names of titular sees are drawn also in numerous cases from those of former dioceses which were absorbed into other dioceses or expanded and hence moved to larger towns and cities. Since 1970, there are two more exceptions. Diocesan bishops who resign their see or are transferred to a non-diocesan appointment are no longer habitually transferred to a titular see. Instead, they take the title Bishop (or Archbishop) Emeritus of the last see. Also, coadjutors are no longer named to titular sees, instead taking the title Coadjutor Bishop (or Coadjutor Archbishop) of the see they will inherit. In other cases titular bishops still take a titular see. Beginning in 2019, titular sees are no longer being assigned to new Vicars Apostolic. When Francis Green 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