Saldae was an important port city in the ancient Roman Empire, located at today's Béjaïa. It was generally a crossroads between eastern and western segments of Northern Africa, from the time of Carthage to the disappearance of the Byzantine Empire from the continent.
Saldae was first inhabited by Numidian Berbers. A minor port in Carthaginian and Roman times, it was a border town between Rome and Juba, to the East. It was made officially a Roman colony during the reign of emperor Augustus, which was mentioned by Pliny the Elder in his book, Naturalis Historia. The emperor Vespasian performed a sort of minor ethnic cleansing, by settling it with a great many Roman veterans, increasing its population and importance in the province of Mauretania Caesariensis, later in the fraction Sitifensis. It eventually became part of the province to the East, Mauretania Sitifensis.
In the second or third century AD, Gaius Cornelius Peregrinus, a decurion (town councillor) from Saldae was a tribunus (military commander) of the auxiliary garrison at Alauna Carvetiorum in northern Britain. An altar dedicated to 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 (source).
Conquered by the Vandal Kingdom in 429, and remained a key stronghold. That kingdom fell a century later, conquered by the Byzantines empire, who established an African prefecture, and later the Exarchate of Carthage.
Saldae had disappeared by the end of the first millennium, but was refounded as "Béjaïa" by the Berber Hammadid dynasty (whose capital it became) in the 11th century, and became an important port and cultural center. As a principal town of the Hammadid leader, Emir En Nasser, Béjaïa flourished and was renamed En Nassria. En Nasser's son, el Mansour, built an impressive palace inside the fortifications constructed by his father. The Hammadid Empire fell in 1152, when the Almohad ruler, Abd al-Mu'min, invaded central Maghreb from Morocco. The son of a Pisan merchant (and probably consul), posthumously known as Fibonacci, there learned under the Almohad dynasty about Indian mathematics which he called Modus Indorum, Hindu-Arabic numerals, and introduced them and modern mathematics into feudal Europe, part of the introduction of Islamic classical knowledge that helped spur the Renaissance, lifting Christendom out of the Dark Ages.
- 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."
- Dictionary of Greek and Roman Geography:
"In later times it was the W. limit of Mauretania Sitifensis, against Mauretania Caesariensis in its more contracted sense."
- Béjaïa & the Corniche Kabyle, Morocco, Algeria & Tunisia: a travel survival kit, Geoff Crowther & Hugh Finlay, Lonely Planet, 2nd Edition, April 1992, p. 292.