ORAN (ORAN), DIOCESE OF. - A city and diocese in Algeria, suffragan of the archdiocese of Algiers. It covers an area of 67,353 sq. km. with a population of 1,990,729, of whom 360,000 are Catholics; it has 103 parishes served by 103 diocesan priests and 56 religious; 10 male and 37 female religious communities (*Ann. Pont.*, 1952, p. 302).
The patron of the cathedral is St. Joseph, and his feast is celebrated on the day of his patronage.
In the reorganization of the Churches of Algeria by Gregory XVI, on 9 April 1838, the province of Oran formed part of the diocese of Algiers, from which it was separated and erected as a diocese by Pope Pius IX with the bull *Supremum pascendi munus* of 25 July 1866. The cathedral, formerly dedicated to St. Louis, was consecrated to the Sacred Heart in 1930.
Tertullian states that in his time Christianity had spread as far as the land of the Moors (*Adversus Iudaeos*, 7); but the clergy of this region is known only from the Conference of Carthage in 411, at which were present the bishops Priscus of Quizia, mentioned by St. Augustine, and Germanus of Gypsaria; the region was afflicted by the Donatist heresy. Among the bishops gathered at Carthage by King Huneric in 484, 13 were from the region of Oran.
The Museum of Oran houses a rich collection of Christian epigraphic material from the region; the oldest inscriptions are those of Altava from the beginning of the 4th century (CIL, VIII, nos. 9862, 9885, 21734, 9892, 9855, 9890) with the expression «discessit» while at Guetna is found «decessit», at Albulas «discessit in pace Domini», at Tiarré «recessit» and «acceptus est»; at Castra Nova «recessit in pace»; at Regias and Tascarrus «nos praecessit in pace dominica»; at Pomaria the tomb is indicated as «domus aeternalis», at Numerus Syrorum «invece è detto «domus romula».