A protosyncellus or protosynkellos is the principal deputy of the bishop of an eparchy for the exercise of administrative authority in an Eastern Orthodox or Eastern Catholic church. The equivalent position in the Western Christian churches is vicar general. The protosyncellus is normally a senior priest, archimandrite, chorbishop or auxiliary bishop selected to assist the bishop with his administrative responsibilities. In this capacity the protosyncellus exercises the bishop's executive power over the entire eparchy.