Flint Castle was the first of a series of castles built during King Edward I's campaign to conquer Wales. The site was chosen for its strategic position in North East Wales. The castle was only one day's march from Chester, supplies could be brought along the River Dee and there was a ford nearby across to England that could be used at low tide.
Building work began in 1277 initially under Richard L'engenour, who would later become Mayor of Chester in 1304. When work ceased in 1284, Flint Castle had an inner ward and an outer bailey. They were separated by a tidal moat and were connected with gatehouse and drawbridge. A plantation town was also laid out beyond the outer bailey. The inner ward had three large towers and a detached keep. This isolated tower protected the inner gatehouse and outer bailey.
Flint, on the western shore of the River Dee estuary, could be supplied by river or sea. Its harbour was protected by a defensive wall. The castle lies opposite to the English shore and Shotwick Castle in England. Before the course was changed in the 18th century, passage across the estuary at this point could be made directly by boat at high tide or by fording at low tide.
During the English Civil War, Flint Castle was held by the Royalists. It was finally captured by the Parliamentarians in 1647 after a three-month siege. To prevent its reuse in the conflict, the castle was then slighted in accordance with Cromwell's destruction order. The ruins are what remain today.
By the 19th century part of the site's outer bailey was used as Flintshire's County Jail. A quarry operated nearby.
The castle is based on Savoyard models where one of the corner towers is enlarged and isolated. This independent structure served as both corner tower and keep or donjon. The keep is an impressive structure. Its stone walls are 7 metres thick at the base and 5 metres above. Access was gained by crossing a drawbridge into a central entrance chamber on the first floor. Originally there would have been at least one additional storey. These floors had small rooms built into the thick walls. A timber gallery was built on top of the keep for the visit of Edward, Prince of Wales, in 1301. On the ground floor is a vaulted passage that runs all the way around the inside of the keep.
Flint's design was not repeated in any other castle built by Edward I in North Wales. The layout at Flint remains unique within the British Isles.
Flint Castle, which has been managed as public monument for 90 years, is now maintained by Cadw, a Welsh-government body that protects, conserves and promotes the building heritage of Wales. Access is free and via a path. Most parts of the castle, such as the isolated keep, are open to the public.
References:The Gravensteen is a castle in Ghent originating from the Middle Ages. The name means 'castle of the counts' in Dutch. Arnulf I (918–965), Count of Flanders, was the first to fortify this place, building a medieval bastion on this high sand dune, naturally protected by the river Leie and its marshy banks. This bastion consisted of a central wooden building and several surrounding buildings, also in wood.
In the early 11th century, the wooden building was replaced by a stone residence, consisting of three large halls that made up three storeys, connected by a stone stairwell. The monumental stone staircase, the light openings, the fireplaces built into the walls and the latrines were signs of considerable luxury and comfort in those days. There was probably also a tower.