Nesactium was an ancient fortified town and hill fort of the Histri tribe. In pre-Roman times, Nesactium, ruled by its legendary king Epulon, was the capital of the tribal population of the peninsula called Histri, who were also connected to the prehistoric Castellieri culture. Some theories state a later Celtic influence, but who they were and where they came from has never been discovered for certain. It is believed that their main economic activities were trade and piracy all over the ancient Mediterranean Sea.
In 177 BC, the town was conquered by the Romans and destroyed. Rebuilt upon the original Histrian pattern, it was a Roman town until 46–45 BC, when the Ancient Greek colony Polai was elevated to Pietas Iulia, today Pula. The town was located on the ancient road Via Flavia, which connected Trieste to Dalmatia. The area was abandoned by the Romans in the 6th century, following the Slav invasions.
At the end of the fourth century, the walls were renewed. Two churches were added, next to each other, between the bathhouse and the forum. The southern one, the largest, was probably dedicated to Mary and used for the daily ceremonies; the northern one was used for baptisms and religious ceremonies. There are traces of fire, which may have something to do with the Avar attacks on Histria in 600 and 611.
References:The historical centre of Briançon is a strongly fortified town, built by Vauban to defend the region from Austrians in the 17th century. Its streets are very steep and narrow, though picturesque. Briançon lies at the foot of the descent from the Col de Montgenèvre, giving access to Turin, so a great number of other fortifications have been constructed on the surrounding heights, especially towards the east.
The Savoyards made two raids into French territory in 1691 and 1692. As a result, Vauban was dispatched to inspect the frontier defences, which had been ill-equiped to deal with the attack from Savoy. He returned to the area in 1700 to check on the progress that had been made since his first visit. When Vauban visited Briançon, work on the defences had already started under a local engineer, Monsieur d"Angrogne in 1692.