Wales emerged as a nation from the collapse of Romano-British Britannia following the invasions of the Angles, Saxons and Jutes from the fifth century AD onwards. What is now known as Wales was for a time known as 'North Wales', while [[Devon]] and [[Cornwall]] (in SW England) were 'West Wales' until their conquest. The Mercian king [[Offa]] (Mercia equates roughly to the English Midlands) created an substantial earthwork, [[Offa's Dyke]] running between the [[Irish Sea]] and the [[River Severn|Severn]] estuary in the later eighth century to separate his kingdom from Welsh lands. The dyke broadly marks the Anglo-Welsh boundary to this day.
The [[Norman Conquest]] of England following 1066 gave rise to Norman attempts to occupy Wales; by the thirteenth century much of eastern and southern Wales were under Norman control in autonomous 'Marcher Lordships' owing loyalty to the English crown. What was left of independent Wales was not a unitary nation, but comprised a number of separate, often warring, principalities, and only late on, under English pressure, did these unite to acknowledge one 'Prince of Wales'. These princes were provided by the most powerful of the Welsh states, Gwynedd, in the mountainous NW of the country. Most notable was [[Llewelyn the Great]] , who was successfully married to King John's illegitimate daughter (1173-1240; who unified the country, and gave it a code of laws). His grandson, [[Llewelyn ap Gruffydd]], was unable to resist a powerful invasion mounted by the English king [[Edward I]], and his death in battle in 1282 and the later execution of his brother Daffyd (executed for treason due to his betrayal of the English king, with whom he had previously been allied) marked the extinction of independent Wales.
A number of huge fortifications were built by Edward to pacify the country, notably that of [[Caernafon Castle]], and maintained by his successors. These castles wer known as the ''Iron Ring''.