IN the summer of 1320, at a session of the estates that later came to be known as the Black Parliament of Scone, an assize of noblemen passed judgment on a group of conspirators charged with seeking to overthrow Robert I (1306–29) in favour of Edward Balliol. Among the culprits were a senior member of the royal household, the aged countess of Strathearn, several other prominent land holders and a handful of knights and esquires. All were deeply dissatisfied with the king's recent efforts to reward the families who had supported him in the difficult years leading up to Ban-nockburn and to designate as traitors any of his subjects who refused to acknowledge his claim to the throne. The conspiracy never really got off the ground but the general consensus among the scholars who have studied the plot is that it represented a clear and present danger to the king and a sobering reminder (if any were needed) that in 1320 the Bruce claim to the kingship was still a source of deep division within political society.

The Black Parliament is noteworthy alone for the spectacle that attended its sitting. It is all the more remarkable because Robert summoned the assembly with the principal aim of staging a dramatic manifestation of one of the most important prerogatives associated with later medieval kingship: the exercise of justice. The king's decision to confront the members of the so-called Soules conspiracy in a lawfully constituted meeting of parliament reflected more than merely the need to quell opposition as quickly and as openly as possible. More significantly, it spoke to a shrewd appreciation on Robert's part of the potential inherent in high status assemblies to protect, promote and enhance prerogatives that he considered the specific preserve of the crown, especially in matters relating to the law. Interpretations of the reign of Robert I have argued that the king ‘ruthlessly’ and ‘blatantly’ manipulated parliamentary procedure in order to project an image of legitimacy both within and beyond the kingdom of the Scots. Robert's defeat of Edward II's English army at Bannockburn may have won him the hearts and minds of many subjects, noble and commoner, but, however impressive the victory, it failed to quell opposition to his rule among the friends and adherents of the Balliol family.