The two men came to an agreement that unless the castle was relieved by the English by 24 June then it would be returned to Scottish control. It was this deal which led, inevitably, to the battle of Bannockburn.
On 23 June Mowbray left Stirling to meet Edward II. Technically, the castle had now been relieved, so there was no longer the need to fight. Knowing the terrain, and having observed the Scots’ preparations, Mowbray warned the king against taking on Bruce – but Edward ignored his advice.
Fleeing from the battle, Edward II headed for Stirling Castle, only to find the gates barred against him. Mowbray realised that it was only a matter of time before the victorious Scots took the castle, so it was the last place that Edward should be. Mowbray later switched sides and was killed in Ireland fighting alongside Edward Bruce in 1318.