The northern most anchor of Wat's dyke was a stronghold called Dinas Bassing. According to Nicholas, this was felt to be of Saxon origin, but the beginnings are unknown. The area was first inhabited by the iron age peoples leaving their hill forts, cairns, and circles. The Ordovices are credited with building some of the fortifications. [ See: Prehistoric England and Wales, by James Dyer, Penguin Books, pp. 346-347.] The area was also occupied during the Roman period. Its location on the coastal road to NW Wales was certainly a strategic military location. Its "heyday" was during the kings of Mercia where Offa's [Offa's Dyke fame!] own son Cenwulf was reported to have died there in the year 821 AD.
The abbey was founded in 1131 AD by Ranulf, Earl of Chester. [The Order of Savigny established 14 such abbeys in Britain. See: "The Abbeys & Priories of Medieval England", by Colin Platt, pp.26-27. A view from the air is shown on p. 207.] However, this Order was merged with the Cistercians in 1147 AD and the monks took on the "white habit" of the Cistercian. [It was officially made a Cistercian abbey by Henry II in 1159 AD.]
It was during the summer of 1277 AD that Edward I established his personal head-quarters here while the castle of Flint was being constructed. It was only a matter of time until the conquest of Llewelyn was completed. (Statutum Wallie of 12 Edward I) [ See: "The Welsh Wars of Edward I", by John E. Morris, pp.130-132.]
Just north along the coastal road is Mostyn. Just west in the town of Whitford. Holywell surrounds the abbey, and Flint Castle is to the south. All these locations were to become the home of my family's DNA. Certainly a strategic location it is.