When the Great Council developed into what we understand by the word "parliament," it took its place as one of a series of competitors for the chief power in the kingdom. The king's prerogative was sufficient to cover everything that he was able to do, and an undefined law of treason[77] gave him a valuable weapon, which he did not fail to use. The most notable danger to the prerogative was the supersession of the royal power by the rise of certain noble families from time to time. The strength of these nobles lay in the number of their retainers, over whom they had absolute power. Most of them were hereditary sheriffs of their own districts, and it was rarely that either king or parliament ventured seriously to interfere with their judicial powers. The Parliament found an additional rival in the Secret--afterwards called the Privy--Council, which formed the Executive of the realm. Little is known of the early history of this important body. Its origin has generally been ascribed to the Parliament of 1369, which, as we have seen (cf. pp. 40, 41), appointed a Committee to discuss certain matters before they came before Parliament.[78] This, however, refers to the Lords of the Articles, and when the Committee of the Articles was appointed two years later, the precedent of 1369 was avowedly followed. It is not, therefore, possible to identify this body with the king's secret council, mentioned two years later, when urgent private business, relating to the succession, was discussed "in the king's secret chamber in his secret council,"[79] as contrasted with the king's chamber of public Parliament.[80] This allusion to a secret council probably indicates not the origin, but the existence, of such a secret council of royal advisers as must have come into being centuries before. The small place held by the Parliament in the government of the country left the Executive or Secret Council a still more valuable instrument for those in power, and it is impossible that the kings of Scotland did not possess a private council before 1369. The next definite reference is in 1389; when the Duke of Rothesay was appointed regent for Robert III (cf. p. 75), his power was limited by a council, of which eighteen members were appointed by the Estates--probably an enlarged form of the Secret Council.[81] But this was only a temporary arrangement, and it is very doubtful if Mr. Hill Burton is right in treating the King's Secret Council as one of "the three great Committees of Parliament."[82] It is more natural to regard it as analogous to the English Curia Regis, and not ultimately connected with parliamentary institutions. Like the English Curia Regis, it exercised judicial powers from an early period, probably in connection with its general work of administrative order. It is not easy to distinguish between the jurisdiction of the Council, and that of the Lords Auditors, or Committee of Parliament, elected from 1369 onwards,[83] to decide legal cases, and a further