The Welsh March
The Normans became masters of England, a centralised kingdom, in a matter of a few years.
Wales, far more decentralized than England, proved resistant to the Normans' power. During the reign of William II, the Welsh rose in revolt, and by 1100 the Normans had been driven out of Gwynedd, Ceredigion and most of Powys.
Gruffudd ap Cynan became ruler of Gwynedd and Cadwgan ap Bleddyn ruler of Powys. Gruffudd ap Rhys ap Tewdwr sought to establish himself in Deheubarth.
In the uplands of the borders and the South East, members of the old Welsh royal families struggled to retain a degree of authority.
Thus Wales became divided between those regions still under native rule and the lordships controlled by the castles of the Normans - between Pura Wallia and Marchia Wallie. The Norman lords of the March, while subjects of the English king, were not subject to the law of England.
Their fiefdoms were like independent kingdoms whose rulers could, with impunity, hold courts, build castles and wage war.
As the March would exist in some form for over 450 years, it became a major and lasting element in the history of Wales.
