ate, Edward's Welsh lands included the four
cantreds of Perveddwlad, and the districts of Cardigan and Carmarthen.
Young as he was, he had competent advisers, and, while he was still in
Aquitaine, designs were formed of setting up the English shire system
in his Welsh lands, so as to supersede the traditional Celtic methods
of government by feudal and monarchical centralisation. Efforts were
made to subject the four cantreds to the shire courts at Chester; and
Geoffrey of Langley, Edward's agent in the south, set up shire-moots at
Cardigan and Carmarthen, from which originated the first beginnings of
those counties. The bitterest indignation animated Edward's Welsh
tenants, whether on the Clwyd or on the Teivi and Towy. They rose in
revolt against the alien innovators, and called upon Llewelyn to
champion their grievances. Llewelyn saw the chance of extending his
tribal power into a national principality over all Wales by posing as
the upholder of the Welsh people. He overran the four cantreds in a
week, finding no resistance save before the two castles of Deganwy and
Diserth. He conquered Cardigan with equal ease, and prudently granted
out his acquisition to the local chieftain Meredith ap Owen. Nor were
Edward's lands alone exposed to his assaults. In central Wales Roger
Mortimer was stripped of his marches on the upper Wye, and Griffith ap
Gwenwynwyn, the lord of upper Powys, driven from the regions of the
upper Severn. In the spring of 1257 the lord of Gwynedd appeared in
regions untraversed by the men of Snowdon since the days of his
grandfather. He devastated the lands of the marchers on the Bristol
Channel and slew Edward's deputy in battle. "In those days," says
Matthew Paris, "the Welsh saw that their lives were at stake, so that
those of the north joined together in indissoluble alliance with those
of the south. Such a union had never before been, since north and south
had always been opposed." The lord of Snowdon assumed the title of
Prince of Wales.

Edward was forced to defend his inheritance. Henry III. paid little
heed to his misfortunes, and answered his appeal for help by saying:
"What have I to do with the matter? I have given you the land; you must
defend it with your own resources. I have plenty of other business to
do." Nevertheless, Henry accompanied his son on a Welsh campaign in
August, 1257. The English army got no further than Deganwy, and
therefore did not really invade Llewelyn's dominions at