Saldae was an important port city  in the ancient Roman Empire, located at today's Béjaïa (in Kabylia, eastern Algeria). It was generally a crossroads between eastern and western segments of Northern Africa, from the time of Carthage to the disappearance of the Eastern Roman Empire from the continent.
The Princeton Encyclopedia of Classical Sites reports:
The Roman period has left more abundant remains. Vestiges of the ramparts are visible at several places....Of the monuments which have been preserved or noted, particularly interesting are the remains of a temple underneath the church, built on the site of a mosque. The temple was undoubtedly near the forum, whose location is indicated by the bases of statues. In the immediate vicinity the public baths have produced a large ornamental mosaic (a piece of it is on exhibit in the church). Other public baths were on the site of the Civil Hospital. Two similar mosaics were found there; they depict heads of Oceanus flanked by Nereids. One is at the Algiers Museum, the other at the town hall of Bejaia. A third public bath was located near the high school.Cisterns and basins are still visible (indeed, still in use) at several places in the upper town. They were fed by the Toudja aqueduct, which brought water from springs located 21 km to the West....West of the middle town a rounded depression has been supposed variously to have been the site of a circus, an amphitheater, and a theater. No ancient remains are known that settle the question. A single inscription (CIL, VIII, 8938) mentions "ludi circenses".Many Roman sculptures have been found in the area around the town, some carved in the rock, some found in the ground, others as sarcophagi. A sarcophagus with strigils is at the Louvre. Few sculptures come from Saldae itself, mainly some capitals and votive stelae dedicated to Saturn.
The city grew in size with new buildings and the emperor Vespasian settled the city with many Roman veterans, increasing its population and importance in the province of Mauretania Caesariensis, and when that was divided, in the new province of Mauretania Sitifensis.
The city was under the Roman ius (law) and its citizens were endowed with full civil rights. Saldae was a center of a Mauretania Caesariensis area fully Romanised, that in the late third century was even fully Christian.
In the 3rd century AD, Gaius Cornelius Peregrinus, a decurion (town councillor) of Saldae, was a tribunus (military commander) of the auxiliary garrison at Alauna Carvetiorum, in northern Britain. An altar dedicated by him was discovered shortly before 1587 in the north-west corner of the fort, where it had probably been re-used in a late-Roman building ().
Vandal, Byzantine and modern era
In the 5th century, Saldae became the capital of the short-lived Vandal Kingdom of the Germanic Vandals, which ended in about 533 with the Byzantine conquest, which established an African prefecture and later the Exarchate of Carthage.
After the 7th-century Arab conquest, Saldae declined and had practically disappeared by the end of the first millennium.
Christianity survived the Arab conquest, the disappearance of the old city of Saldae, and the founding of the new city of Béjaïa. A letter of Pope Gregory VII (1073–1085) exists, addressed to clero et populo Buzee (the clergy and people of Béjaïa), in which he writes of the consecration of a bishop named Servandus for Christian north Africa.
It has had a long list of incumbents, mostly of the lowest (episcopal) rank, a few of intermediate (archiepiscopal) rank:
- Albertus, Friars Minor (O.F.M.) (1415 – 1442)
- Johannes Frey, O.F.M. (1457.08.19 – 1474.04.08)
- Erasmus Perchinger, O.F.M. (1482.11.06 – 1483.09.26)
- Mathias Schach, Carthusians (O. Cart.) (1495.11.19 – 1515.11.05)
- Konrad Mair (1517.07.21 – 1522)
- Hieronim Antoni Szeptycki (1739.07.20 – 1759.09.24)
- Ignatius Krzyzanowski (1762.06.14 – ?)
- Bernard-Claude Panet (Titular bishop 1806.07.12 – 1819.01.12), later Titular Archbishop (1819.01.12 – 1825.12.04)
- Daniel O’Connell, O.E.S.A. (1834.04.25 – 1867.07.10)
- Joseph-Henri-Jean-Marie Prud’homme (1937.01.29 – 1952.01.05)
- Hélder Pessoa Câmara (Titular Bishop 1952.03.03 – 1955.04.02), later Titular Archbishop (1955.04.02 – 1964.03.12)
- Titular Archbishop Henri-Martin-Félix Jenny (1965.05.15 – 1966.02.15)
- Marie-Joseph Lemieux (マリー・ジョゼフ・ルミュー) (1966.09.24 – 1994.03.04), later bishop and stil later Archbishop
- Sylvester Carmel Magro, O.F.M., (1997.03.10 – ...), Apostolic Vicar of Benghazi
This titular see has, confusingly, for a long time concurrently had a counterpart (also Latin) called Bugia, the Italian form of Béjaïa, the modern name of former Saldae. Thus Bugia was the alternative title borne lastly by George Hilary Brown, titular bishop of from 5 June 1840 until 22 April 1842, when he became bishop of Liverpool.
- Saldae (in Italian)
- Pliny the Elder: Natural History
"Rusazus, a colony of Augustus, Saldae, a colony of the same, Igilgili likewise; the town of Zucca, situated on the sea and the river Ampsaga."
- M. Leglay, "Saldae (Bejaia or Bougie) Algeria" in Richard Stillwell et alii (editors), The Princeton Encyclopedia of Classical Sites (Princeton University Press, 1976)
- British Museum, Description of the altar
- Stefano Antonio Morcelli, Africa christiana, Volume I, Brescia 1816, p. 269
- H. Jaubert, Anciens évêchés et ruines chrétiennes de la Numidie et de la Sitifienne, in Recueil des Notices et Mémoires de la Société archéologique de Constantine, vol. 46, 1913, pp. 127-129
- J. Mesnage, L'Afrique chrétienne, Paris 1912, pp. 8 e 268-269
- Annuario Pontificio 2013 (Libreria Editrice Vaticana 2013 ISBN 978-88-209-9070-1), p. 963
- Geoff Crowther & Hugh Finlay. Béjaïa & the Corniche Kabyle, Morocco, Algeria & Tunisia: a travel survival kit. Lonely Planet, 2nd Edition, April 1992
- Serge Lancel et Omar Daoud. L'Algérie antique : De Massinissa à Saint Augustin. Place des Victoires, 2008 (ISBN 9782844591913)
- Mommsen, Theodore. The Provinces of the Roman Empire Section: Roman Africa. (Leipzig 1865; London 1866; London: Macmillan 1909; reprint New York 1996) Barnes & Noble. New York, 1996
- Reynell Morell, John. Algeria: The Topography and History, Political, Social, and Natural, of French Africa. Publisher N. Cooke. London, 1854 ( )
- Bugia, concurrent Italian modern name, also as a separate Catholic titular see
- Caesarea of Mauretania
- Romano-Berber states
- Regnum Maurorum et Romanorum
- Christian Berbers