Coming from a leading family in the Quercy, Saint-Sulpice's father, Jean Ébrard, Seigneur de Saint-Sulpice was a client of Constable Montmorency and then Catherine de Medici, serving as an ambassador and governor to the young prince Alençon, brother to the king.
At this time the king's other brother Anjou, future Henri III began to draw him away from Alençon into his service.
He fought at the Battle of Dormans in which the duke of Guise vanquished a German mercenary force that had invaded the kingdom.
[2] This was a region that was dominated by Protestant military leaders in the early religious wars that Henri desired more control over.
Introduced to the future Henri III that same year, he would receive his martial education under the tutelage of his father in the household of Alençon.
[3] During 1572 he was made a gentilhommes de la chambre by Charles IX, succeeding his father who had previously held the position.
[14] Saint-Sulpice participated in the siege of La Rochelle in 1573, the city having entered rebellion in the wake of the Massacre of Saint Bartholomew.
Before departing Saint-Sulpice ensured that much of his wealth was converted into jewels, such that it could be more easily transported from France, to this end he bought a gold chain for 500 écus.
[17] At this time Saint-Sulpice was also close to Retz, and accompanied him when he provided private advise to the king, elevating his station at the Commonwealth court.
[10] He was with Henry I, Duke of Guise during the campaign that culminated at Dormans as a commander in his father's ordinance company, alongside other favourites of the king.
[24][2] With the estates due to open in December, D'O strongly urged Saint-Sulpice to attend, arguing that it was good for him to make social displays.
Unsuccessful in this he put on a friendly façade for the young favourite, but secretly commissioned the vicomte de Tours to kill him.
[27] This would not last however and, at 11pm on 20 December, after having attended a ball, he received an invite from the vicomte for what he assumed was a duel, on route to the location, he was ambushed outside the porte du Foy by several assassins who stabbed him with daggers, he died an hour later in his fathers arms.