Religious disputes had become a grave concern, threatening the peace of the kingdom. Phelypeaux took a pragmatic approach, trying to calm down passions on either side. He was one of the five deputies that the young king Louis XIII sent in 1616 to negotiate the Treaty of Loudun. The reconciliation of the queen mother with the young king was in part his work. In 1621 the peace broke down with a Protestant uprising. The king went on campaign and Pontchartrain followed him. He feel ill at the siege of Montauban, and died at Castel-Sarrazin on 21 October 1621 at the age of fifty-two. He left memoirs that cover the events from 1610 to 1620,  giving a clear and simple account of the events he had witnessed and accounts of other events, a valuable historical source. His son Louis was just nine years old when he died. Raymond Phélypeaux assumed the position of Secretary of State for Protestant Affairs,  saying that he would hold it until Louis came of age, but in fact the position remained in the La Vrillière side of the family. Notes  Citations  Sources