The coming of Christianity
Christianity came to Wales in the early fourth century and Welsh churches remained bastions of the faith in the years following the departure of the Romans in the fifth century. In the sixth century St David founded monasteries throughout the country, and after the Norman invasion of England in the 11th century, when some parts of east and south Wales were occupied by Norman marcher lords, there was a spate of ecclesiastical building.
In the first decades of the 13th century Wales enjoyed a period of near total unification under Llewelyn Fawr (the Great). The Welsh began to build stone castles as bases for their forces to resist continual raiding and more serious invasions by Norman-English lords, who erected numerous castles on the borders. Some of these Welsh-built castles, notably Castell-Y-Bere in North Wales, were captured by Edward I during his invasion of Wales and he used them to consolidate his power over the rebellious principality.
The English Occupation
After Edward's successful invasion of Wales, the English king sought to maintain his control over Wales, particularly North Wales which had given him the most trouble, by constructing 10 new substantial castles. These were to be administrative centres as well as army quarters and were strategically sited to command the coast, river crossings, or key roads. Among these great buildings, which in some cases took nearly 40 years to complete, were the castles of Beaumaris, Caernarfon, Conwy, Fflint, Harlech (captured in 1404 by Owain Glyndwr and used as base for his rebellion against Henry IV) and Rhuddlan.
The Prince of Wales
In 1284 Edward I was in Wales following his successful conquest of the country. His wife, Eleanor, gave birth to a son and heir, Edward, while they were staying at some hastily built lodgings at Caernarfon. There has long been a tradition unsupported by any evidence, that Edward held up his baby at a gathering of Welsh nobles and said "Here is your new Prince of Wales." In reality it was not until Edward was 17, in 1301, that he was created Prince of Wales. Ever since it has been customary for the monarch to create his or her eldest son Prince of Wales.
Seven of Edward's successors have failed to become king, namely;
the Black Prince;
Edward, son of Henry VI;
Edward, son of Richard III;
Arthur, son of Henry VII;
Henry Frederick, son of James I;
James Stuart, the Old Pretender, whose father James II fled the throne in 1688;
and Frederick , son of George II
Conversely, only 11 of the 31 kings from Edward II to the present day were first Prince of Wales, namely;
Charles II was never formally invested, while the current Prince of Wales is still heir to the throne. The age each was created Prince of Wales has varied considerably:
George II was only five days old while George V was well into his thirties. Every Prince of Wales has as his motto the words adopted by the Black Prince from the King of Bohemia at the Battle of Créçy: Ich Dien, "I serve".