Background
Charles de Valois was the illegitimate son of Charles IX and Marie Touchet. He was born at the Château de Fayet in Dauphiné on the 28th of April 1573. His father, dying in the following year, commended him to the care and favour of his younger brother and successor, Henry III, who faithfully fulfilled the charge. His mother then married François de Balzac, marquis d'Entragues. One of their daughters (Charles's half-sister) named Catherine Henriette afterwards became the mistress of Henry IV.