It was founded by the Romans as the market town of Venta Silurum, an important settlement of the Brythonic Silures tribe.

It remained prominent through the Roman era and Early Middle Ages as the site of a road crossing between several important civic centres.

Historian John Newman has described the walls as: "easily the most impressive town defence to survive from Roman Britain, and in its freedom from later rebuilding one of the most perfectly preserved in Northern Europe.

"[5] In 1881, a portion of a highly intricate coloured floor mosaic or tessellated pavement, depicting different types of fish, was unearthed during excavations in the garden of a cottage.

[9] The rudimentary quality of most of the houses, few of which had mosaic or hypocaust-heated floors, indicates that, although a large settlement, Caerwent did not attain the importance or sophistication of other Romano-British tribal capitals.

A large number of Christian burials, some stone-lined, dating from between the 4th and 9th centuries have also been discovered, both around the town's East Gate and close to the parish church.

[14] During World War II, a Royal Navy Propellant Factory was established at Caerwent, immediately north of the A48 road.

[16] Caerwent is now a small village, largely bypassed by the busy A48 road running between the city of Newport to the west and Chepstow to the east.