What is "apostolic prefect"

Prefect \Pre"fect\, n. [L. praefectus, fr. praefectus, p. p. of praeficere to set over; prae before + facere to make: cf. F. pr['e]fet.]

1. A Roman officer who controlled or superintended a particular command, charge, department, etc.; as, the prefect of the aqueducts; the prefect of a camp, of a fleet, of the city guard, of provisions; the pretorian prefect, who was commander of the troops guarding the emperor's person.

2. A superintendent of a department who has control of its police establishment, together with extensive powers of municipal regulation. [France]
   --Brande & C.

3. In the Greek and Roman Catholic churches, a title of certain dignitaries below the rank of bishop.

   Apostolic prefect (R. C. Ch.), the head of a mission, not of episcopal rank.
   --Shipley.

An apostolic prefect or prefect apostolic is a priest who heads what is known as an apostolic prefecture, a missionary area where the Catholic Church is not yet sufficiently developed to have it made a diocese.

If a prefecture grows and flourishes, it may be elevated to an apostolic vicariate, headed by a titular bishop, in the hope that with time the region will generate enough Catholics and stability for its Catholic institutions, to warrant being established as a diocese.

The usual sequence of development is: mission, prefecture, vicariate, diocese.

The apostolic prefecture and the apostolic vicariate are to be distinguished from the territorial abbacy (formerly called an " abbey nullius").