Henry de Percy, 1st Baron Percy the commissioning of Warwolf, a giant trebuchet which flattened the curtain walls. The defenders had tried to surrender four days earlier, but had been made to wait by the king while he tried out his new toy. In September 1305 the first joint English and Scottish parliament met at Westminster to agree a constitution for the unified state, with Percy playing a leading role in the negotiations, but Robert Bruce, a leading representative of the Scots, was already conspiring to rebel. On 25 March 1306 Robert Bruce was crowned King of Scotland at Scone Abbey, upon which Edward confiscated his
Wars of Scottish Independence around 2,000 Scots had been slain. Edward Balliol then had himself crowned King of Scots, first at Perth, and then again in September at Scone Abbey. Balliol's success surprised Edward III, and fearing that Balliol's invasion would eventually fail leading to a Scots invasion of England, he moved north with his army. In October, Sir Archibald Douglas, now Guardian of Scotland, made a truce with Balliol, supposedly to let the Scottish Parliament assemble and decide who their true king was. Emboldened by the truce, Balliol dismissed most of his English troops and moved to Annan, on the north shore of