By the early 2nd century during the reign of Hadrian, the civitas had begun construction work on a market place and developing centre of local government.

A bowl with a chi-rho symbol shows that early Christian worship had begun in the late 3rd century.

The walls have been described 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.

[3] According to traditional accounts in the Vitae Sanctorum Britanniae, a monastery was founded by Saint Tatheus in about the 6th century.

Tradition holds that Caradog Freichfras of Gwent moved his court from Caerwent to Portskewett around the 6th century.

[3] 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.