He was descended from an old family which had for generations served the dukes of Burgundy and Lorraine, and after being educated with his brothers in Bavaria and Italy, was introduced to the court of King Henry IV of France in 1598.
In 1615 Bassompierre had purchased from Henri, duc de Rohan, the coveted position of colonel-general of the Swiss and Grisons; on this account he was sent to raise troops in Switzerland when Louis XIII marched against Savoy in 1629, and after a short campaign in Italy his military career ended.
In 1625, he was sent into Switzerland on an equally futile mission, and in 1626 to London to secure the retention of the Catholic ecclesiastics and attendants of Henrietta Maria, wife of King Charles I of England.
His share was only a slight one, but his wife was an intimate friend of Marie de' Medici, and her hostility to the cardinal aroused his suspicions.
[1] During his embassy to Charles I of England in 1626, Bassompierre was entertained by the Master of the Ceremonies Sir Lewes Lewkenor, who escorted him to a play, 'Lucnar came to bring me a very rich present from the king, of four diamonds set in a lozenge, and a great stone at the end; and the same evening sent again to fetch me to hear an excellent English play.