Edward was never reconciled to the treaty. In 1332 he backed a rival claimant to the Scottish throne, Edward Balliol, son of King John I of Scotland. By 1333 England and Scotland were formally at war again when Edward besieged Berwick, starting the Second War of Scottish Independence. The Scots felt compelled to attempt to relieve the town. A Scottish army 20,000 strong attacked the 10,000 English and suffered a devastating defeat at the Battle of Halidon Hill. Berwick surrendered the next day.