The princes of North Wales had long been a sharp thorn in the side of England. Neither force nor friendly alliance had been strong enough to keep them quiet. The love of independence, the inheritance of proud, although illusory traditions, the attachment of an affectionate people, the possession of remote mountain fastnesses, the antipathy as strongly felt towards the Norman as it had been towards the Saxon, combined to prevent either peace or submission. All the other races had combined on the soil of Britain, the Welsh would not. The demands of feudal homage made by the kings of England were evaded or repudiated; the intermarriages, by which Henry II. and John had tried to help on a national agreement had in every case failed. In every internal difficulty of English politics the Welsh princes had done their best to embarrass the action of the kings; they had intrigued with every aspirant for power, had been in league with every rebel. At the beginning of the reign of Henry III. they had conspired with Falkes de Breauté against the Marshalls; at the close of it they were in intimate alliance with the Montforts. Not only so; the necessity of guarding the Welsh border had caused the English kings to found on the March a number of feudal lordships, which were privileged to exercise almost sovereign jurisdictions, and exempted from the common operations of the English law. The Mortimers at Chirk and Wigmore, the Bohuns at Hereford and Brecon, the Marshalls at Pembroke, and the Clares in Glamorgan, were out of the reach of the king, and often turned against one another the arms which had been given them to overawe the Welsh. There they had an open ground for combats which they could not wage where English law was strong. So long as the Welsh were left free to rebel the Marchers must be left free to fight. [Sidenote: Rebellion of Llewelyn, Prince of North Wales, and his brother David. ]