[2] The same triliteral root can also mean "craftsman", "artisan", &c.[3] The city was established as a colony on the maritime trade route between Phoenicia and the Strait of Gibraltar.

[1] Iomnium, not Iol, is also probably the Ioulíou (Ancient Greek: Ἰουλίου) mentioned by the Periplus of Pseudo-Scylax, the present text probably representing a scribal error of the original name.

[1] The great basilica of Iomnium, also referred to as the cathedral, as it seems likely that a church of this scale housed the seat of the bishop himself,[12] stands between the Byzantine and Roman ramparts, but much closer to the latter, from which it is separated by only a few metres.

At Tipasa, the cathedral church was also positioned in this way, but with an additional feature:[13] due to the imperatives of orientation, it was the main façade that faced the rampart, and not the apse, as was the case at Iomnium.

The Iomnium portal, on the other hand, seems to have opened onto a street or square, as can be seen from the fairly irregular paving stones covering the ground in front of the entrance.

The exception is the façade of the central nave and two-thirds of the south wall, which are built of ashlar of various sizes, laid out in a disorganised manner, with small blocks filling the gaps.

No doors opened onto the aisles; instead, a triple bay gave access to the nave, framed by four large pillars preserved at varying heights.

A significant discovery is an inscription found inside, mentioning the towns of Rûsuccuru and Iomnium, suggesting a civic or religious use, perhaps linked to trade or worship.

The discovery of another building on the western flank of the cape, consisting of terraces rising up to the level of the town, suggests sophisticated urban organisation and intelligent use of the natural relief.

Despite modifications made during the Berber period, distinctive architectural features have been preserved, including an inscription carved in relief on one of the blocks uncovered, providing valuable information about the building's function and history.

The presumed entrance to the room, aligned on the south axis, is marked by a threshold measuring 1.70 m by 0.60 m, set between two columns with an attic base and an Ionic capital.

The description of the basilica that has now disappeared, located in the southern part of the town against the Roman wall, reveals foundations buried under the road and lots 30, 31 and 32.

The basement had been transformed into a pothole after being flooded, while the upper floor, backfilled to a depth of around one metre, revealed no visible plan but retained a basilica shape.

The tympana of the arcades, some of which are inlaid in the Administration building, have been discovered, featuring various motifs such as a six-leaf rosette and a star formed from two interlaced squares.

Its careful construction, in small rubble stones bound with hydraulic mortar, is reminiscent of the African fortifications erected under Roman rule from the 1st to 3rd centuries.

Clear traces of the rampart are also visible in the rocks bordering the sea, suggesting a methodical construction that could date back to the reign of the Vandal king Genseric (455-477).

The wall, built of large cut blocks stacked one on top of the other with no visible cement, is remarkably well preserved along most of its length, although it is often composed of a single course of ashlar.

To compensate for this technical inferiority, the enclosure was cleverly designed, with a series of redans and curtain walls featuring narrow gateways, such as the main gate, discovered almost intact with its huge stone hinges and leaves.

The most visible parts of the Byzantine rampart are at its eastern and western ends, where the wall extends into the sea to prevent attacks from the shallow coastline.

Despite signs of hasty construction using salvaged materials, a few Christian decorative elements, such as rosettes and monograms, have been found, suggesting occupation after the time of Genseric.

The island, uninhabitable due to its steep slopes, today houses just one ruin, a small vaulted chamber offering a panoramic view over the town.

It was covered by three square slabs, one of which bore the letters M F L. This feature suggests a burial that was temporarily hidden for unknown reasons, perhaps linked to religious persecution, such as that associated with Donatism.

[18] The presence of large landowners, including the emperor, suggests a landscape characterised by vast estates, private properties and imperial lands.

On a sandstone slab measuring approximately 0.51 x 0.76 x 0.09 metres, an unartistic representation is carved in bas-relief, characterised by its indecency, which made it difficult to describe at the beginning of the 20th century.

Above the phallus, two lines engraved in characters 15 mm high bear the following three words: "Bibe, mandu[c]a, suc[c]ur[re]", which could be translated as the imperative verbs "drink, eat and relieve".

[23] This dedication underlines the importance of inner courtyards, veritable sacred forecourts or porticoes, in the life of sanctuaries built in Africa in Roman times in honour of Punic deities more or less transformed by the prevailing syncretism.

[25] Most of the oil mills in the Tigzirt and Taksebt region appeared to have a similar plan, with small buildings divided into two rooms, only one of which showed remains of a press.

[26] Thus, along the entire coastal range, many rocky outcrops feature basins and grooves, falsely interpreted by early Europeans as sacrificial stones where the blood of victims flowed.

The proliferation of these oil mills implies a fairly high population density, which was difficult to accommodate entirely within the two narrow enclosures of Tigzirt and Taksebt.

The territory of Tigzirt, although limited, was organised in a simple manner, probably influenced by the history of the surrounding towns, and there is much to suggest that Roman settlement forced the natives to migrate to more remote lands.