The siege of Alnwick Castle (July 1462) saw a Yorkist army capture the castle, which changed hands repeatedly between 1461 and 1464.
After the battle of Towton Alnwick was held by the Lancastrians, but in September 1461 it surrendered to the earl of Warwick. Yorkist control of the castle was short-lived and in November it was captured by Sir William Tailboys.
The Lancastrian successes in Northumberland owed a great deal to Scottish support. James III of Scotland was still a child in 1462, and most power was held by his mother and regent, Mary of Guelders. Her attitude to the Lancastrians was initially unenthusiastic, although this changed when Margaret of Anjou offered to surrender Berwick to the Scots. Berwick changed hands on 25 April 1461 and for a short time Mary became a Lancastrian supporter. By the following year her support had waned somewhat, and in April 1462 she paid for Margaret to visit France, where she hoped to gain more active supporters.
While Margaret was away the earl of Warwick had two meetings with Queen Mary. After the failure of the first meeting Warwick raided southern Scotland, and at a second meeting Mary agreed to a truce that was to last from June until the end of August 1462.
This gave Warwick the time he needed to recapture Alnwick and Bamburgh. In July a force under William Hastings, Lord Hastings and Sir John Howard attacked Alnwick, and after a short siege the castle surrendered. A Yorkist garrison was placed in the castle, and for a short period only Dunstanburgh was held for the Lancastrians.
The situation changed in October when Queen Margaret returned from France with some official support and a force of soldiers led by Pierre de Brézé. They landed near to Bamburgh, and after a brief siege Alnwick surrendered. The earl of Warwick was sent north to deal with this threat. Another siege of Alnwick followed, this time lasted from December 1462 to 6 January 1463. Once again the Yorkist success would be short-lived. Alnwick was retaken by the Lancastrians in March 1463 when Sir Ralph Grey, the castle's commander, changed sides, and it remained in Lancastrian hands until the aftermath of their defeats at Hedgeley Moor and Hexham in 1464.