His parents died in Paris of smallpox in 1724, leaving him and his remaining siblings, including Marie Louise, orphans.

He was entrusted to his grandfather Hercule Mériadec, Duke of Rohan-Rohan, who raised Soubise to the court, where he became the companion of Louis XV, who was the same age as he.

He accompanied Louis XV in the campaign of 1744–48 and attained high military rank, which owed more to his courtiership than to his generalship.

[1] Soon after the beginning of the Seven Years' War, through the influence of Madame de Pompadour, he was put in command of a corps of 24,000 men, and in November 1757 he sustained the crushing defeat of Rossbach.

He was more fortunate, however, in his later military career, and continued in the service until the general peace of 1763, after which he lived the life of an ordinary courtier and man of fashion in Paris.