In the parliament of July 1321, Edmund briefly sided with the opposition when he agreed to exile the Despensers, but later claimed this had been done under duress, and in November sat on the council that annulled the exile. In October, Edmund was once more employed in a move against Badlesmere, when he took part in a siege on Leeds Castle in Kent, which was held by Badlesmere. After Badlesmere was forced to surrender, hostilities moved to the Welsh Marches, where Roger Mortimer and others were in open revolt. Once confronted with the royal army, Mortimer surrendered without a fight, and attention turned to the leader of the baronial opposition, Thomas of Lancaster. Edmund, who had taken part in the Marcher campaign, was now ordered, with the Earl of Surrey, to take Lancaster's castle of Pontefract. On 17 March 1322, Lancaster was captured after his defeat at the Battle of Boroughbridge and brought to Pontefract. Here, Edmund was on the jury that condemned him to death for treason. Even with Lancaster defeated, the battle against the rebels was not over. Edmund was charged with overtaking Wallingford Castle from Maurice de Berkeley in January 1323, a task which he fulfilled with great success. For his loyalty, Edmund was rewarded with substantial holdings in Wales, primarily land forfeited by Roger Mortimer. The greater part of the spoils of war, however, went to the Despensers, who both benefited greatly from the forfeiture of the rebels. By 1326, the Despensers, father and son respectively, enjoyed incomes of £3,800 and £7,000, while Edmund's annual income was at only 2,355 marks (£1,570). Scotland and France With domestic opposition largely neutralised, the king turned his attention to Scotland. A major campaign was organised in August, but the effort ended in total failure when the English were routed by the Scots, led by Robert the Bruce, at the Battle of Old Byland on 14 October 1322. Edward II himself had to flee the battlefield to avoid capture, and Edmund was with him as the royal army retreated to York. The king's inability to handle the Scottish situation was becoming apparent. Andrew Harclay, who had defeated Lancaster at Boroughbridge, and for this had been created Earl of Carlisle and appointed Warden of the Marches to Scotland, signed a peace treaty with the Scots without royal sanction in January 1323. When the king found out, he ordered Harclay's arrest. Edmund