How did William the Conqueror try to gain control over Wales?

Answer 1

By building huge, impregnable castles. An example is Caerphilly Castle it is one of the great medieval castles of western Europe. Several factors give it this pre-eminence - its immense size (1.2h), making it the largest in Britain after Windsor, its large-scale use of water for defence and the fact that it is the first truly concentric castle in Britain. Of the time of its building in the late 13th century, it was a revolutionary masterpiece of military planning One of Henry III's most powerful and ambitious barons, Gilbert de Clare, lord of Glamorgan, built this castle. His purpose was to secure the area and prevent lowland south Wales from falling into the hands of the Welsh leader Llywelyn the Last, who controlled most of mid and north Wales. De Clare built other castles on the northern fringes of his territory for the same purpose, such as Castell Coch. He had seized the upland district of Senghenydd, in which Caerphilly lies, from the Welsh in 1266 to act as a buffer against Llywelyn's southward ambitions. Llywelyn realised the threat and tried but failed to prevent the castle from being built; it was begun on 11 April 1268, was attacked by Llywelyn in 1270, and was begun again in 1271. This time it was completed without hindrance. Its message was not lost on Llywelyn, who retreated northwards.

Answer 2

By circa 13th century Wales was divided between native Welsh principalities and the territories of the Anglo-Norman Marcher lords. The leading principality of the time was Gwynedd whose princes gained control of the greater part of the country, making the other remaining Welsh princes their "vassals", and had then decided to take the title Prince of Wales". English monarchs had made several attempts to seize control of the native Welsh territories, it was not until Edward's war of conquest against Llywelyn ap Gruffudd ("Llywelyn the Last") of 1277 to 1283 that this was achieved on any lasting basis.

In the two campaigns, of 1277 and 1282/1283, Edward first significantly reduced the territory of the Principality of Wales and then completely overran it, as well as the other remaining Welsh principalities. Most of the conquered territory was retained as a royal land, and these lands subsequently became, by custom, the territorial endowment of the heir to the English throne with the title Prince of Wales. The remainder would be granted to Edward's supporters as new Marcher lordships. Although the territories would not be effectively incorporated into the Kingdom of England until the Laws in Wales Acts 1535-1542, Edward's conquest marked the end of Welsh independence.