The body of advisers appointed to advise the monarch. It wasan offshoot of the *curia regis composed of the king’s tenants-in-chief, house-hold officials, and indeed anyone else the king chose. From it grew largercouncils, which in turn emerged as *parliament. It was named ‘privy’ as itwas for the private advice of the monarch, although it lacks executive power.
*Source: A Dictionary of Medieval Terms & Phrases by Christopher Coredon with Ann Williams
From St. Louis’ letter of advice to advice his eldest son, the later Philip III:
And I wish here to tell you what is related concerning King Philip, my ancestor, as one of his council, who said he heard it, told it to me. The king, one day, was with his privy council, and he was there who told me these words. And one of the king’s councillors said to him how much wrong and loss he suffered from those of Holy Church, in that they took away his rights and lessened the jurisdiction of his court; and they marveled greatly how he endured it. And the good king answered: “I am quite certain that they do me much wrong, but when I consider the goodnesses and kindnesses which God has done me, I had rather that my rights should go, than have a contention or awaken a quarrel with Holy Church.” And this I tell to you that you may not lightly believe anything against the people of Holy Church; so love them and honor them and watch over them that they may in peace do the service of our Lord.