In the range of its functions the council was often more important than the Estates in the running the country. Its registers include a wide range of material on the political, administrative, economic and social affairs of Scotland. The council supervised the administration of the law, regulated trade and shipping, took emergency measures against the plague, granted licences to travel, administered oaths of allegiance, banished beggars and Gypsies, dealt with witches, recusants, Covenanters and Jacobites and tackled the problem of lawlessness in the Highlands and the Borders.
Like the Parliament, the Council was a development of the King's Council. The King's Council, or curia regis, was the court of the monarch surrounded by his royal officers and others upon whom he relied for advice. It is known to have existed in the thirteenth century, if not earlier, but has left little trace of its activities.
By the later fifteenth century the council had advisory, executive and judicial functions though surviving records are mainly confined to the last. It is at this period that the 'secret' or privy council makes its formal appearance when, in February 1490, parliament elected 2 bishops, an abbot or prior, 6 barons and 8 royal officers to form the king's council for the ostensioun and forthputting of the King's authorite in the administracioun of justice.
Until 1707, The Privy Council met in what is now the West Drawing Room at the Palace of Holyroodhouse in Edinburgh. It was called the Council Chamber in the 17th century.