Kidwelly castle began life as an earth and timber fortification established by Bishop Roger of Salisbury in 1106AD to defend the Norman route into south-west Wales. It was built in a crescent shape, with the river Gwendraeth guarding its back, and a deep ditch fortifying the frontal approach.

This was a volatile area of Wales in the years following the Norman conquest, and Kidwelly fell to the welsh on a number of occasions. It was captured by Lord Rhys in 1159AD. It is believed that he torched the castle at this time, but he is also credited with rebuilding the castle in 1190AD. By 1201AD, the castle was back in Norman hands, and remained that way for the duration of its military life. Owain Glyndwr attempted to capture it in 1403AD with the assistance of French and Bretton soldiers, but was thwarted by the arrival of English reinforcements three weeks into the siege.

During the 14th and 15th Centuries, the de Chaworth family slowly enhanced Kidwelly's fortifications, with a stone curtain wall being added, along with towers, battlements and an imposing gatehouse. The gatehouse took over a hundred years to complete, and was finally finished in 1422AD.

By the early 17th Century, Kidwelly had fallen out of use as a fortified residence, and was serving as a judicial court. It can be assumed that the castle was already in a semi-ruinous state at this time. Subsequently, it passed out of the pages of history.

The extensive fortifications of Kidwelly along with its peripheral role in the English civil war contributed towards its preservation in an exceptionally high sate of repair.

Today, Kidwelly is one of the finest castles in the south west of Wales. The impressive five-story gatehouse dominates the public approach to the castle. The interior precinct is large, offering magnificent views from the extensive wall walks.

Although located near a modern town, the castle is located at a suitable distance from the main areas of development, and protected from their sprawl by its presence on the banks of the River Gwendraeth. Indeed, Kidwelly Castle manages to retain a feeling of isolation, with expansive rural vistas adding to the atmosphere and sense of space.