Icosium
ICO´SIUM (Ἰκόσιον: Algier), a city on the coast of Mauretania Caesariensis, E. of Caesarea, a colony under the Roman empire, and presented by Vespasian with the jus Latinum. (Itin. Ant. p. 15; Mela, 1.6.1; Plin. Nat. 5.2. s. 1; Ptol. 4.2.6.) Its site, already well indicated by the numbers of Ptolemy, who places it 30′ W. of the mouth of the Savus, has been identified with certainty by inscriptions discovered by the French. (Pellissier, in the Exploration Scientfique de l'Algérie, vol. 6. p. 350.) Many modern geographers, following Mannert, who was misled by a confusion in the numbers of the Itinerary, put this and all the neighbouring places too far west. [Comp. IOL]
[P.S]A Punic settlement, placed on four islets and a narrow coastal strip and protected by a natural acropolis. The name is known from Solinus (25.17), from a Punic stela, and especially from a hoard of 158 lead coins bearing the name IKOSIM. The town was chosen by Roman colonists even before the annexation of Mauretania; at that time it was connected to the colony of Ilici in Spain. It became a Roman colony under the Flavians, grew in the 2d and 3d c., but never became an important town. A Christian community existed in the 4th c. and three bishops are known in the 5th. The town was sacked in 373 during the revolt of Firmus. The Ziridian prince Bologguîn founded a new town on the site in 960.
Facing the islets in the bay, the Roman town stretched out along the coast with the hill behind it. It was protected by a rampart with towers. Parts survive today in several places. The walls were often reused in the Berber defenses of the 10th c. and the Turkish ramparts of the 16th. Thus, the fortifications enclosed part of the modern kasbah to the SW and the Bab-el-Oued district to the NE. They extended as far as the former Bresson square to the SE. Outside, villas surrounded by gardens were located on the coastal plain and, more often, on the sides of the hills. The villas have produced sculptures: two female heads, a statue of Pomona, another statue of a female deity, a head of the emperor Hadrian; all are in the Algiers Museum. Inside the lower town, which was densely populated, a network of streets at right angles to each other formed insulae. Their plan can often be traced in the modern urban grid. The decumanus maximus followed the modern Bab-Azoun street. The water supply was provided at least in part by wells; for example, at the so-called Nave well there are stacks of pottery dating from Punic to mediaeval times.
Of the monuments discovered or noted inside the town, the public baths are of particular importance. Four cisterns placed side by side and two ornamental mosaics indicate that a first bath building was under the old cathedral. A second was located under the former church of Notre Dame des Victoires. A third has been discovered in the suburbs to the SE, near the Jardin d'Essai. According to the inscription (CIL VIII, 9256), a mithraeum no doubt existed. No church is known, but two capitals and a fenestella confessionis (at the Algiers Museum) indicate the presence of an edifice for Christian worship.
The main necropolis was located NW of the town along the extension of the decumanus. Funerary stelae, cinerary urns, rock-cut tombs, and burials under roof tiles have been discovered. In addition, there were tombs in the form of vaulted cellars; entering by an underground passage, one reached the burial chamber, where niches cut into the walls sheltered cinerary urns. Abundant grave goods have been found, in particular terra sigillata and intact glass vases. One enameled glass goblet was decorated with a scene of gladiators. There was another necropolis SE of the town at the other end of the decumanus. There are isolated tombs at the periphery.
BIBLIOGRAPHYS. Gsell, Atlas archéologique de l'Algénie (1911) 5, no. 12; M. Leglay, “A la recherche d'Icosium,” Antiquités Africaines 2 (1968) 7-52MPI.
M. LEGLAY