AMBANJA, APOSTOLIC PREFECTURE OF. — Located in insular Africa, it is the rare apostolic prefecture of Isola Santa Maria, Nossi-Bè and Mayotte (the latter belonging to the Comoro group), and was erected in 1848, by dismemberment from the apostolic vicariate of Madagascar, and enlarged (1858) with the annexation of the remaining Comoro Islands (La Grande-Comore, Anjouan, Moheli). After the definitive detachment (1898) of Isola Santa Maria, the jurisdiction was extended to the districts of Sambirano and Maromandia (Madagascar), ceded by the vicariate of Diego Suarez; on 2 February 1932, the prefecture was entrusted to the Capuchins of Alsace, and its territorial limits were precisely defined at the same time. The name was changed to that of A. by decree of 14 June 1938.
The area of the territory is 14,780 sq. km., and the total population is 240,000 inhabitants, namely 128,155 Muslims, 64,233 pagans, 4,936 Catholics (of whom 3,723 are indigenous), and 821 catechumens. The missionary apostolate, entrusted to 16 Capuchin priests and two lay brothers, and three French sisters of Calais, is carried out effectively, especially among the Malagasy of the Malagasy districts.