Byzantine ecclesiastical titles and offices

A protosyncellus, protosynkellos or protosyngel () 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.

Synkellos (), latinized as syncellus, is an ecclesiastical office in the Eastern Rite churches. In the Byzantine Empire, the synkellos of the Ecumenical Patriarch of Constantinople was a position of major importance in the state, and often was regarded as the successor-designate to the reigning patriarch.

Oikonomos (, from - 'house' and - 'rule, law'), Latinized œconomus, oeconomus, or economos, was an Ancient Greek word meaning "household manager." In Byzantine times, the term was used as a title of a manager or treasurer of an organization.

The nomophylax (, "guardian of the laws") was a senior Byzantine judicial office of the 11th–15th centuries.

A chartophylax (, from χάρτα, "document" and φύλαξ, "guard, keeper"), sometimes also referred to as a chartoularios, was an ecclesiastical officer in charge of official documents and records in the Greek Orthodox Church in Byzantine times.

Skeuophylax (), feminine form skeuophylakissa (σκευοφυλάκισσα), meaning "keeper of the vessels", is an ecclesiastical office in the Eastern Orthodox Church.

Exokatakoiloi (), latinized as Exocatacœli, was a term attested since the 11th century for the principal officials of the Patriarch of Constantinople or a bishop of the Eastern Church: these were the steward or oikonomos (the patriarchal official was prefixed with megas, "grand"), the treasurer or [megas] sakellarios, the sacristan or [megas] skeuophylax, the record-keeper or chartophylax, and the head of the sakellion. Later, a sixth member was added, the protekdikos.

The dikaiophylax (, "guardian of the laws") was a Byzantine judicial office of the 11th–15th centuries.