Consecration And The Diocesan Bishop's Authority

An Orthodox bishop is consecrated by at least two, and ordinarily three, already-consecrated bishops, a plurality required for validity that parallels Catholic practice and traces to shared early church custom before the two traditions' eleventh-century separation. Election to a vacant see is carried out by the Holy Synod of the relevant autocephalous church, typically from a slate of eligible monastic clergy, a process that varies in its specific procedures from one Orthodox church to another since each autocephalous church governs its own internal affairs, including episcopal elections, without a shared universal canon law of the kind the Roman Catholic Church's single Code of Canon Law provides across all Latin dioceses worldwide.

Larger or historically significant dioceses may have auxiliary or vicar bishops assisting the diocesan bishop, and some Orthodox churches maintain titular sees, historic dioceses no longer functioning territorially, to which auxiliary bishops or bishops serving in diaspora and missionary roles outside the church's traditional territory are formally assigned, a practice that keeps the ancient territorial names of dioceses lost to conquest or population change, many in formerly Christian regions of the Middle East and Asia Minor, in continued canonical use.