Conquered by Ancient Rome, it was turned into a military colony by the emperor Claudius for the conquest of the kingdoms of Mauretania.

A wall of approximately 7,500 feet (2,300 metres) was built around the city for defense against nomadic tribes, and Roman public buildings and districts of houses were constructed within the enclosure.

[9][6] Most of the inhabitants, however, continued to be non-Christian until, according to legend, Salsa, a Christian maiden, threw the head of their serpent idol into the sea, whereupon the enraged populace stoned her to death.

The body, miraculously recovered from the sea, was buried, on the hill above the harbour, in a small chapel which gave place subsequently to the stately basilica.

[12] The newcomers gave it the name Tefassed, which translated from the Arabic language means badly damaged[clarification needed].

The town and its surroundings is home to the largest Berber-speaking group of western Algeria, the Chenoua people.

[6] Inside the Roman ruins, facing the sea and Mount Chenoua, a stele was erected in 1961 in honor of Albert Camus with this phrase in French, extracted from his work Noces à Tipasa: “I understand here what is called glory: the right to love beyond measure " (« Je comprends ici ce qu'on appelle gloire : le droit d'aimer sans mesure. »).

In 2022, the IPCC Sixth Assessment Report included it in the list of African cultural sites which would be threatened by flooding and coastal erosion by the end of the century.