Bishops are Gaalite religious officials. They are ordained priests who hold office by virtue of Companionate Inheritance - an institution that draws its legitimacy from Gaal's Companions. Just as the Companions were charged to spread the faith and minister to specific communities after the Redeemer's death, so are bishops their spiritual descendants, whose authority is recognized by parish priests and laypeople alike. Because the Gaalite religion has spread since the days of the Companions, the number of bishops has grown. To become a bishop in the True Confession, one must be an ordained priest who has entered the Black Clergy, and become a hieromonk. Parish priests, burdened with family, cannot advance to become bishops. As the number of bishoprics or eparchies is limited, a position to take up a bishop's service must be available (or created by a superior). Furthermore, bishops must be invested by a superior, typically an archbishop or a metropolitan, and usually be granted approval by a secular ruler. A bishop has the power to ordain priests, tonsure monks and admit ordained priests into the Black Clergy, consecrate holy ground, receive special vows from laypeople pursuing a saintly path, and to consecrate holy items and allow them to channel divine power. Bishops must wear special vestments to effect these rituals. Bishops may also participate in ecclesiastical councils which determine religious doctrine and sometimes rule on important social or political questions. The size of an eparchy varies, but most lands possess at least one, and up to two dozen or more eparchies that are administered by a single bishop. Eparchies that include particularly important cities (perhaps with a population of 10,000 or more) are presided over by archbishops. The latter have powers identical to a bishop as well as the power to anathemize straying members of the flock. Individual lands are headed by a metropolitan bishop (or simply, a metropolitan). These latter may invest bishops and crown kings or princes. The five most authoritative bishops that control the most ancient eparchies are called patriarchs. Patriarchs can place entire eparchies or lands under interdict. Eparchies are often themselves owners of substantial tracts of land, as well as villages, hamlets, and occasionally, towns. Effectively, a bishop functions as the land's owner, until it is transferred to a successor in the event of a bishop's death. Bishops are addressed as "My Lord", "my Lord Bishop", or my Holy Lord".