In 1618 the young prince entered royal service under Charles Bonaventure de Longueval, Count of Bucquoy, for the campaign against the Bohemian Revolt that opened the Thirty Years' War.

[1] Barbançon raised a regiment at his own expense with the intention of supporting Charles Emmanuel I, Duke of Savoy in the War of the Mantuan Succession, but with the changing situation in Italy and the Low Countries he remained in the Low Countries to fight the Dutch.

On 27 April 1634 the Marquis of Aytona, on Philip IV's orders, had Barbançon arrested for having corresponded with Cardinal Richelieu in the context of the Conspiracy of Nobles (1632).

Information against him had been provided by Balthazar Gerbier, Charles I of England's resident agent in Brussels.

Only in 1658 was he again commissioned as a royal officer, being appointed commander of the garrison of Ypres and captain general of artillery.