The battle was obstinately fought, but was decided by the desertion of the Welsh tenants, and by the Welsh bowmen in Mortimer's service turning their bows against his men-at-arms; and, finally, the English were defeated, with the loss of eleven hundred men, Sir Edmund himself being made a prisoner.
After the battle the Welsh behaved with the greatest savagery; killing all the wounded, stripping the fallen, and horribly mutilating their bodies.

The news created great excitement at Alnwick and, had not the situation in the north been critical, Percy would have gathered his forces and marched, with all speed, to avenge the defeat and capture of his brother-in-law.
The Earl of Dunbar, with many of the tenants of his former estates, and numbers of the English borderers, had entered Scotland and carried out considerable raids.

In revenge for this, Douglas despatched Thomas Halliburton and Patrick Hepburn, each with a considerable force, to invade Northumberland.

Halliburton ravaged the country as far as Bamborough, collected great spoils, and returned with them.

Hepburn, who had a still larger force, penetrated farther into England, carried his ravages to within a few miles of Alnwick; and then retired north, with an enormous amount of booty.
When, however, he had crossed the border into the country known as the Merse, north of Berwick, the Earl of Dunbar fell upon him at West Nesbit, and completely defeated him.