Located above cliffs on the River Wye, construction began in 1067 under the instruction of the Norman Lord William FitzOsbern.

Originally known as Striguil, it was the southernmost of a chain of castles built in the Welsh Marches, and with its attached lordship took the name of the adjoining market town in about the 14th century.

It was subsequently held by two of the most powerful Anglo-Norman magnates of medieval England, William Marshal and Richard de Clare.

Chepstow Castle is situated on a narrow ridge between the limestone river cliff and a valley, known locally as the Dell, on its landward side.

There is no evidence for a settlement there of any size before the Norman invasion of Wales, although it is possible that the castle site itself may have previously been a prehistoric or early medieval stronghold.

[5] The site overlooked an important crossing point on the River Wye, a major artery of communications inland to Monmouth and Hereford.

[7] It was constructed in stone from the first (as opposed to wood, like most others built at this time), marking its importance as a stronghold on the border between England and Wales.

[7] In 1270, the castle was inherited by Roger Bigod, 5th Earl of Norfolk, who was a grandson of William Marshal's eldest daughter, Maud.

It was garrisoned in response to the rebellion of Owain Glyndŵr in 1403 with twenty men-at-arms and sixty archers but its great size, limited strategic merit, geographical location and the size of its garrison all probably contributed to Glyndŵr's forces avoiding attacking it, although they did successfully attack Newport Castle.

From the 16th century, after the abolition of the Marcher lords' autonomous powers by King Henry VIII through the Laws in Wales Acts of 1535 and 1542, and Chepstow's incorporation as part of the new county of Monmouthshire, the castle became more designed for occupation as a great house.

A memorial to Sir Nicholas Kemeys, who led the Royalist defence during the Second Civil war and was killed in combat after refusing to surrender after the castle's fall, lies within the keep.

At the same time, the courtyard of the castle began to be used for local horticultural shows, fêtes, and, increasingly from the 1880s, historical pageants sanctioned by the Duke of Beaufort.

In 1910/11, the castle and adjoining river bed were the site of well-publicised excavations by Dr. Orville Ward Owen, who was attempting to find secret documents to prove that Shakespeare's plays had in fact been written by Francis Bacon.

[12] Chepstow Castle is open to the public, and since 1984 has been in the care of Cadw, the Welsh government body with the responsibility for protecting, conserving and promoting the built heritage of Wales.