The Norman conquest of Wales, a piecemeal penetration over a period of some 130 years, was as much a political as a military advance. The unit of penetration was the Welsh political entities (cantrefi) with the result that lands in Wales were held by right of conquest, not by grant from the king. The initial campaigns were both swift and successful. A chain of castles was established along the north coast and Robert of Rhuddlan succeeded in penetrating through the very heart of Gwynedd to Caernarfon. In mid-Wales Roger of Montgomery, following the valley of the Dee into Powys, over-ran the cantrefi of Arwystli, Cydewain and Ceri. By 1099 Deheubarth (south Wales) seemed to have disappeared as castles were established from Cardiff to Swansea, Brecon, Cardigan and Pembroke. But 1094 saw the return from exile of Gruffudd ap Cynan of Gwynedd (north Wales) who had been the prisoner of Hugh of Chester. Gradually, lost lands were regained and new conquests consolidated in the north though the Welsh ‘revolt’ in the south had less spectacular success. By 1135, though west and north Wales were once more in Welsh hands, Deheubarth was an Anglo-Norman province.

That year, in the confused situation in England following the death of Henry I, a new ‘revolt’ broke out; the years 1135 to 1197 saw a great Welsh awakening. Owain Gwynedd continued the expansion of Gwynedd begun by his father Gruffud ap Cynan and in 1165 took the title princeps Wallensium as leader of a Welsh military confederation. After his death in 1170 Rhys ap Gruffudd continued the struggle. He was appointed justiciar of south Wales by Henry II in 1172, recognition of his right to hold the lands which he had won. He became the Lord Rhys and the independence of Deheubarth and of the lesser lordships under his protection was asserted in their uneasy relationships with the neighbouring Anglo-Norman lordships to the west and east. By the time of his death in 1197, a balance had been struck.