Flint Castle was built by King Edward I as the first part of his "Iron Ring" intended to facilitate the conquest and subjugation of Wales. Work began in 1277AD and was completed in 1284AD. Work was briefly interrupted in 1282AD when a Welsh revolt resulted in an attack against the castle.

Alongside the castle, the fortified town of Flint was also built, which would eventually become the administrative centre of Flintshire. This was a "plantation" town - settled with English colonists with a view to establishing an English presence in Wales.

Once finished, Flint Castle consisted of a walled inner ward surrounded by a tidal moat accessed via a drawbridge and gatehouse, defended by a tower at each corner. The south-east "great tower" served as a keep and stood higher than the other three towers, dominating both the inner and outer baileys. It was detached from the main structure allowing it to be protected by its own moat and drawbridge and accessed via the inner ward. A further wall created an outer bailey, stretching down towards either side of the inner ward, protected by its own outer ditch and moat. Beyond that was the township, laid out in a formal plan and defended by a wooden palisade and ditch.

Built on the shores of the estuary of the River Dee, Flint Castle could be re-supplied by sea. It was also a day's march from Chester, making it a very strategic location. Along with the unique design of the castle (based upon a continental model not seen elsewhere in Britain) and its unusually thick walls, this made it highly defensible.

In 1294AD, Flint was attacked during the revolt of Madog ap Llywelyn. The constable of the castle ordered the town be burned to the ground to deny the attackers shelter and food, preventing a siege of the castle.

Flint Castle is most famous as the location of a meeting in 1399AD between Richard II and Henry Bolingbroke (later Henry IV) - an event immortalised in Shakespeare’s Richard II.

During the English Civil War, Flint Castle was held by Royalists. Parliamentarian forces subsequently laid a three-month siege. Once captured, they "slighted" the castle putting it beyond use and resulting in the ruin that remains to the current day.

When visiting Flint Castle, it can be hard to gain an impression of how the site was once laid out. The changing patterns of the Dee mean that the estuary is now much further out, making it hard to imagine how its waters once surrounded the inner ward and outer bailey. The wall of the outer bailey is still visible in fragmented form, with a stretch of flat grass separating it from the wall of the inner ward. Most of the inner ward survives, although the great tower is considerably reduced in height. Nothing remains of the medieval town, although it is easy to recognise its boundaries in the modern street layout.

Flint Castle is a bit of a sad sight today. It feels a little neglected, and its proximity to the town results in the usual litter of beer cans and associated urban detritus. That being said, the ruins are interesting, and the location is quite striking - located in a liminal space between the modern town and the evocative wilderness of the Dee estuary, straddling two different ages as it slumbers.