After the yielding of his chief adversary, King Edward thought that there was no further need for his presence in the North. Accordingly he returned home with the bulk of the army, leaving Warwick with ten thousand men, commanded by Norfolk and the Earl of Worcester, to finish the siege of Alnwick. Somerset lay with them, neither overmuch trusted nor overmuch contemned by his late enemies. Warwick's last siege, however, was not destined to come to such an uneventful close as those of Bamborough and Dunstanburgh. Lord Hungerford and the younger de Brézé made no signs of surrender, and protracted their defence till January 6th 1463.
On that day, at five o'clock in the dusk of the winter morning, a relieving army suddenly appeared in front of Warwick's entrenchments. Though it was mid-winter, Queen Margaret had succeeded in stirring up the Earl of Angus--the most powerful noble in Scotland and at that moment practical head of the Douglases--to lead a raid into England. Fired by the promise of an English dukedom, to be given when King Henry should come to his own again, Angus got together twenty thousand men, and slipping through the Central Marches, and taking to the Watling Street, presented himself most unexpectedly before the English camp. With him was Peter de Brézé, anxious to save his beleaguered son, and the Queen's French mercenaries.
For once in his life Warwick was taken by surprise. The Scots showed in such force that he thought himself unable to maintain the whole of his lines, and concentrated his forces on a front facing north-west between the castle hill and the river. Here he awaited attack, but nothing followed save insignificant skirmishing; Angus had come not to fight, but only to save the garrison. When the English blockading force was withdrawn, a party of Scotch horse rode up to the postern-gate of the castle and invited the besieged to escape; accordingly Lord Hungerford, the younger de Brézé, Sir Richard Tunstal, and the great majority of the garrison, hastily issued forth and joined the relieving force. Then Angus, to the surprise of the English, drew off his men, and fell back hastily over the Border.
Warwick had been quite out-generalled; but the whole of his fault seems to have been the neglect to keep a sufficient force of scouts on the Border. If he had known of Angus's approach, he would have been able to take proper measures for protecting the siege. But the main feeling in the English army was rather relief at the departure of the Scots than disgust at the escape of the garrison. "If on that day the Scots had but been bold as they were cunning, they might have destroyed the English lords, for they had double their numbers," writes the chronicler. The thing which attracted most notice was the fact that the renegade Somerset showed no signs of treachery, and bore himself bravely in the skirmish, "proving manfully that he was a true liegeman to King Edward." Henceforth he was trusted by his colleagues.