The city of Tharros was probably founded by the Phoenicians at the end of the 8th century or possibly in the early 7th century BC in an area already populated during the Nuragic period (n. 7). The main evidence of the Phoenician colony of Tharros is represented by the necropolises and the tophet (n. 6), which was a typical Phoenician and Punic open air sanctuary or sacred burial area, because the settlement itself has not been located yet (it is currently an active archaeological site). The Phoenician necropolises are located in the area of Cape San Marco (n. 23)  and the modern village of San Giovanni di Sinis (n. 1). In the necropolises cremated corpses, along with rich burial goods including jewelry, were buried in circular or elongated shaped pits dug into the sand. Since the 7th century BC, thousands of cinerary urns, containing the burnt bones and ashes of children and sacrificed animals, were deposited in the tophets together with hundreds of sandstone stelae, small votive monuments often representing small temples and divine symbols.
During the second half of the 6th century BC, Tharros was conquered by the Carthaginians, who constructed several new buildings, including the monumental temple and the city’s defensive wall. During the 5th century BC, a handicraft district (n. 8) that specialized in iron metallurgy was created near the tophet in the west, at a time when the use of the sanctuary was increasing.

During the Punic period, the dead of Tharros were buried in a supine position, along with the typical vessels of the period and other personal objects, into chambers carved in the rock in the same funeral areas used during the Phoenician period.
The time between the Roman conquest of Sardinia (238 BC) and the end of the Roman Imperial age (5th century AD) was the period of greatest transformation for Tharros. During the Republican age (2nd century BC), the fortifications of Su Murru Mannu (the great defensive wall, n. 5) were renovated and the so-called Temple K (n. 22) was built. By the 2nd century AD, a new urban system had been established with the construction of roads using slabs of basalt, a volcanic stone, and a very sophisticated sewer system that enabled the dumping of waste waters. Numerous large and grand public buildings were also constructed, among which were three thermal bath complexes (public baths: ns 14, 17, 21) and the Castellum Aquae (n. 13), a structure for distributing fresh water brought into the city from the aqueduct (n. 4). In this period, the funeral practices included both incineration and inhumation (burial of the body in a grave) and a variety of different types of tombs were used.
Unfortunately, during the early Christian period and the High Middle Ages, the principal Roman buildings and the thermal baths suffered severe degradation. This was primarily due to exposure to the elements and the destruction of the ancient structures to provide materials for new construction. A long period of decadence and a slow depopulation followed the raids of the Saracens, although Tharros remained the Episcopal see (the official church seat) until 1071, when the bishop transferred the see to Oristano, which marked the end of the ancient city of Tharros.