Llewelyn saw that they had been preparing their own ruin, and
turned to their former enemy for the redress refused them at
Westminster. David himself made common cause with his brother, and the
spirit of resistance spread among the half-hearted Cymry of the south.
Edward's oppression did more than Llewelyn's triumphs to weld together
the Welsh clans into a single people. A rising was planned in the
strictest secrecy; and on the eve of Palm Sunday, March 21, 1282, David
swooped down on Hawarden, a weak castle in private hands, and captured
it. Llewelyn promptly crossed the Conway and turned his arms against
the royal strongholds of Flint and Rhuddlan, which withstood him,
though he devastated the countryside in every direction. Meanwhile
David hurried south and found the local lords in Cardigan and the vale
of Towy already in arms. With their help he captured the castles of the
upper Towy, but lower down the river Rhys remained staunch to the king,
whereupon David hurried over the hills to Cardiganshire and took
Aberystwyth. North and south were in full revolt.

Edward, taken unawares, prepared to reassert his authority. Certain
faithful barons were "affectionately requested" to serve the king for
pay, and a fairly large army was gathered together, though the
scattered character of the rebellion necessitated its acting in small
bands. Meanwhile the military tenants and the Cinque Ports were
summoned to join in an attack on Llewelyn on the lines of the campaign
of 1277. Edward's task was more difficult than on the previous
occasion. Though Rhuddlan, not Chester as in 1277, had become his
starting-point against Gwynedd, he dared not advance so long as David
threatened his left flank from Denbigh, and the rising in the south was
far more formidable than that of five years before. A considerable part
of the levies had to be despatched to the help of Earl Gilbert of
Gloucester, who was charged with the reconquest of the vale of Towy. On
June 17 as the earl's soldiers were returning, laden with plunder, to
their headquarters at Dynevor, they were suddenly attacked by the Welsh
at Llandilo, and were driven back on their base. Gloucester hastily
retreated to Carmarthen. He was superseded by William of Valence, whose
activity against the Welsh had been quickened by the loss of his son at
Llandilo. Llewelyn then came south, and pressed the English so hard
that for several weeks nothing of moment was accomplished.

The advance ag