In 1277, Llywelyn ap Gruffudd, Prince of Gwynedd, met with Edward I of England in Aberconwy to finalise a treaty that would change the fate of both nations. His hand forced by Edward's invasion earlier that year, Llywelyn's acceptance of the terms confirmed not only short-term peace but also that the rule of Wales would pass to Edward on his death. To augment his rising dominance, the English king embarked on a building project that saw the rise of some of the most recognisable fortresses in Europe. Quite literally, an 'Iron Ring' of castles. Even before the construction of Edward's infamous 'Iron Ring', castles were by no means rare in Wales. Both before and simultaneous to William the Conqueror's establishment of timber and stone fortresses in the south and borderlands, a process continued by many of his descendants, native structures also existed.