Excavations near the Nedern Brook beside the castle revealed a plank from a boat and complex wooden structures in the former river bed.

The discovery of kilns also shows that coarse pottery was produced in the village during Roman times.

The modern Welsh name, Cil-y-coed, meaning "corner of the wood", referring to Wentwood, was proposed by the 19th-century lexicographer William Owen Pughe as the origin of the English name, but his hypothesis has been discredited.

Its entry reads, Durand the Sheriff holds of the King, one land, in Caerwent, called Caldicot.

[6] In 1158 the manor of Caldicot passed to Humphrey II de Bohun, who was responsible for building the stone keep and curtain walls of the present-day castle.

In 1376 it passed to Thomas Woodstock, third son of King Edward III, when he married Alianore de Bohun.

[8][9] Court House was the home of the baker Henry Jones, the inventor of self-raising flour, from 1864 until his death in 1891.

[10] During the first half of the 20th century, Caldicot continued to grow steadily, but unspectacularly, reaching a population of 1,770 in 1951.

Early in the 1950s, however, Chepstow Rural District Council decided that the village should be allowed to expand to approximately 3,000.

Caldicot was designated as a suitable home for the thousands of steelworkers, and expansion plans were revised upwards.

With Caldicot now being part of the "M4 corridor" new businesses, such as the telecommunication company Mitel, came to the town, compensating for the contraction of the steel industry and the railways.

The project was part of the Welsh Government's "21st Century Schools & Education Capital Programme".

The area has popular waymarked footpaths along the Caldicot Levels and the coastal path can be walked.

Caldicot station on the Gloucester–Newport line serves the town, with services to cities like Newport, Cardiff and Gloucester as well to Bristol.