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, like at
Dourdan, France. Flint's keep has been compared to the donjon at
Aigues-Mortes, France. Edward I may have been familiar with Aigues-Mortes having passed through the fortress on the way to join the
Eighth Crusade in 1270. An alternative possibility is the influence of Jean Mésot on
James of Saint George, Mésot having worked in Southern France before influencing Saint George in Savoy. The castle at Flint has also been described as a "classic Carrė Savoyard" as it is very similar to
Yverdon Castle. Its ground dimensions are a third bigger but it shares the classic shape and style, along with the use of a corner tower as keep (donjon). Most historians attribute this to input from Edward's premier architect and castle builder
James of Saint George Although construction began in 1277 and
James of Saint George didn't begin work at Flint until 1280, he was in England from 1278 and was described as "ad ordinandum opera castorum ibidem", that is, charged with the design of the works at Flint. The keep is an impressive structure. Its stone walls are thick at the base and 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. ==History==