But the quiet tenor of his scholar's life was broken by the growing anarchy of Northumbria, and by threats of war from its Mercian rival.

At last AEthelbald marched on a state which seemed exhausted by civil discord and ready for submission to his arms.

But its king Eadberht showed himself worthy of the kings that had gone before him, and in 740 he threw back AEthelbald's attack in a repulse which not only ruined the Mercian ruler's hopes of northern conquest but loosened his hold on the south.
Already goaded to revolt by exactions, the West-Saxons were roused to a fresh struggle for independence, and after twelve years of continued outbreaks the whole people mustered at Burford under the golden dragon of their race.

The fight was a desperate one, but a sudden panic seized the Mercian King.

He fled from the field, and a decisive victory freed Wessex from the Mercian yoke.