Protosyncellus

In this capacity the protosyncellus exercises the bishop's executive power over the entire eparchy.

The title derives from the Greek term syncellus (σύγκελλος), from syn, "with", and kellion, "cell" (Latin: cella).

Synkellos was a term used in the early Church for those monks or clerics who lived in the same cell with their bishops and whose duty it was to be witnesses to the purity of their lives or to perform the daily spiritual exercises in common with them.

In the course of time the patriarchs took two or more syncelli, the most distinguished of whom was called protosynkellos, Latinized as protosyncellus.

Protosyncellus is also the title for the ordinary of an Eastern Catholic Territory dependent on the Patriarch, a missionary pre-diocesan jurisdiction, even if held by or vested in the eparch of an eparchy (full bishopric).