GAO, APOSTOLIC PREFECTURE of. - In French West Africa. It was erected on 9 June 1942 and entrusted to the White Fathers. Its territory was detached from the apostolic vicariates of Bamako, Ouagadougou, and Bobo-Dioulasso, and covered an area of approximately 700,000 sq. km., entirely within the colony of French Sudan, comprising a Saharan or Niger region and a Sudanese region to the south. On 12 June 1947, the Sudanese region was detached from its territory to form the new apostolic prefecture of Nouna, and thus the territory of G. was reduced to approximately 565,000 sq. km. It is traversed by the Niger from west to east.
The climate is hot and dry, and rainfall is scant. The land is sandy, with few trees. Settlements are scattered along the Niger River, which, although an easy means of communication, does not help to make the region fertile. The population exceeds half a million, part of it nomadic. They are of white and black race. There are 24 native Catholics and approximately 290 foreigners. The remainder consists of Muslims, who, after crossing the Sahara with the ancient caravans of trahi, ascended the Niger from the fifteenth and sixteenth centuries in order to take possession of the Sudan. In the south-western part lies the rocky region of Bandiagara, inhabited by the Habè tribe (singular Kado), who are still animists (150,000 inhabitants) but are slowly becoming Islamized. Only at G. is there a quasi-parish. A few other secondary stations are functioning. The apostolate is very difficult, both because of the ease with which the population moves about and because almost all are Muslims, although somewhat liberal and given to superstitions.