The siege of Dunstanburgh Castle of December 1462 was a Yorkist victory that helped secure temporary control of the main Northumbrian castles but that was soon undone. After the battle of Towton the Lancastrians lost control of most of the north of England, but they did keep control of the castles of Dunstanburgh, Bamburgh and Alnwick in Northumberland. Alnwick was the first to fall to a Yorkist army commanded by Richard Neville, earl of Warwick, but Dunstanburgh was close behind. The castle was commanded by Sir Ralph Percy, who had held the post since the 1450s. Percy had lost several close family members fighting for the Lancastrian cause, but Edward IV was aware that his family had popular support in the north, and in an attempt to win him over allowed him to keep command of Dunstanburgh. This was soon proven to be a mistake, and in November Percy surrendered the castle to the Lancastrian force from Scotland commanded by Sir William Tailboys.
In the summer of 1462 the Yorkists recaptured Bamburgh and Alnwick, but not Dunstanburgh. In October Queen Margaret arrived back in England with a force of French mercenaries, and recaptured Bamburgh and Alnwick. Edward responded by sending Warwick north and raising a larger army, which he then led north himself. Faced with such a powerful Royal army the Lancastrian leaders retreated back into Scotland, leaving Henry Beaufort, duke of Somerset and Percy to defend the castles. Somerset and Percy were besieged at Bamburgh, but they were in touch with the garrison at Dunstanburgh, both being coastal castles.
Warwick held the overall command of the siege operations against all three castles, making his base at Warkworth. Lords Scrope, Greystoke and Powis were given direct command of the siege of Dunstanburgh. The defenders of the castle were ill-prepared to withstand a siege, with limited supplies within the castle. The siege began in December, and the defenders were soon short of food. Their only hope of success was a relief army, and a sizable Lancastrian-Scottish army under the French leader de Brézé and the earl of Angus was its way. Warwick managed to keep the news of this from the garrisons of Bamburgh and Dunstanburgh, and on Christmas Eve 1462 Somerset and Percy offered to surrender on terms. Bamburgh was handed over first, followed by Dunstanburgh on 28 December.
Remarkable Edward IV attempted to win over Percy for a second time. He and Somerset both swore allegiance to Edward, and Percy was given command of Dunstanburgh and Bamburgh. Once again this faith was misplaced, and in March 1463 Percy handed the two castles over to Queen Margaret, who was now leading a Lancastrian-Scottish army. The castle remained in Lancastrian hands for over a year, but in April 1464 Percy was killed at the battle of Hedgeley Moor and in May Somerset was captured and executed after the battle of Hexham. With their field army destroyed and their leaders in England dead the garrison on Dunstanburgh opened negotiations and on 25 June 1464 they surrendered on terms. Every member of the garrison was given a pardon. Bamburgh fell in the following month, effectively ending the Lancastrian campaign in Northumberland.