twenty-five years from the appearance of the Conqueror at Chester,
the whole country had been overrun except the mountains of Gwynedd
and the forests of the Deheubarth. This success is easily explained.

For one thing, the Normans had trained, professional soldiers, who
were well horsed and well armed. In a pitched battle the hastily
collected Welsh levies, unused to regular battle and very lightly
armed, had no chance.

Again, the Norman never receded. He was willing to stop
occasionally, in order to bide his time; but he clung tenaciously to
every mile he had won. His skill as a castle builder was as striking
as his prowess in battle or his cautious wisdom in council. He took
possession of an old fortified post, or hastily constructed one of
turf and timber; but he soon turned it into a castle of stone. At
that time the Welsh had no knowledge of sieges; and their impetuous
valour was of no use against the new castles.

Again, the Welsh opposition was not only not organised, but weakened
by internal strife. While the Norman was winning valley after
valley, the Welsh princes were trying to decide by the issue of
battle who was to be chief. Bleddyn was slain in 1075; and his
nephews and cousins tried to rule the country. Among these,
Trahaiarn was a soldier of ability and energy, and a ruler of real
genius. But he was the rival of the exiled princes of the House of
Cunedda, and he found it difficult to bend Snowdon and the Vale of
Towy to his will. Two of the exiles met him, probably near some of
the cairns in the valley of the Teivy; and there, in the battle of
Mynydd Carn, fiercely fought through the dusk into a moonlight night
in 1079, Trahaiarn fell. It looked as if no leader could rise in