The peculiar power of the Estates General was recognized, but was of a kind that could not often be exercised. It was, essentially, a constituent power. The ancient public law of France contained a number of rules called "the fundamental laws of the realm" ("lois fondamentales du royaume"), though most of them were purely customary. Chief among these were rules that determined the succession to the Crown and rules forbidding alienation of the domain of the Crown. The king, supreme though his power might be, could not abrogate, modify or infringe them. But it was admitted that he might do so by the consent of the Estates General. The Estates could give the king a dispensation from a fundamental law in a given instance; they could even, in agreement with the king, make new fundamental laws. The Estates of Blois of 1576 and 1588 offer entirely convincing precedents in this respect. It was universally recognized that in the event of the line of Hugh Capet becoming extinct, it would be the function of the States-General to elect a new king.