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
King of the Romans Papal approval, taking the title as soon as they were crowned in Germany or upon the death of a sitting Emperor if they were elected as heir to the throne. The following were ruling Germanic Kings of the Romans, i.e. men who ruled the Kingdom without subordination to another King but who had not yet been crowned Emperor. The Holy Roman Empire was an elective monarchy. No person had a legal right to the succession simply because he was related to the current Emperor. However, the Emperor could, and often did, have a relative (usually a son) elected to succeed