Council of the Sceptre
From Tolkien Gateway
The nobles and lords of from each of the divisions of Númenor, together with the King's Heir, who gathered to advise the King on weighty matters of state. In the early days of Númenor, the Councillors had no power save that of advice, but when the Shadow fell upon Númenor and the Kings clung to their lives even after their vigor of mind had left them, their power often passed to the members of the Council.