But a fiercer resistance prolonged the independence of the great central portion which alone in modern language preserves the name of Wales.

Comprising in itself the largest and most powerful of the British kingdoms, it was aided in its struggle against Mercia by the weakness of its assailant, the youngest and feeblest of the English states, as well as by an internal warfare which distracted the energies of the invaders.

But Mercia had no sooner risen to supremacy among the English kingdoms than it took the work of conquest vigorously in hand.

Offa tore from Wales the border-land between the Severn and the Wye; the raids of his successors carried fire and sword into the heart of the country; and an acknowledgement of the Mercian overlordship was wrested from the Welsh princes.

On the fall of Mercia this overlordship passed to the West-Saxon kings, and the Laws of Howel Dda own the payment of a yearly tribute by "the prince of Aberffraw" to "the King of London." The weakness of England during her long struggle with the Danes revived the hopes of British independence; it was the co-operation of the Welsh on which the northmen reckoned in their attack on the house of Ecgberht.