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 Walls of Constantinople are a series of defensive stone walls that have surrounded and protected the city of Constantinople (today Istanbul) since its founding as the new capital of the Roman Empire by Constantine the Great. With numerous additions and modifications during their history, they were the last great fortification system of antiquity, and one of the most complex and elaborate systems ever built. They were also the largest and strongest fortification in both the ancient and medieval world.
Initially built by Constantine the Great, the walls surrounded the new city on all sides, protecting it against attack from both sea and land. As the city grew, the famous double line of the Theodosian Walls was built in the 5th century. Although the other sections of the walls were less elaborate, they were, when well-manned, almost impregnable for any medieval besieger.