[1] Guy-Auguste is mostly remembered for an altercation with the young Voltaire in 1725, in which both men insulted each other.
When Voltaire then exercised his right to demand that Guy-Auguste face him in a duel, the Rohan family obtained a lettre de cachet from French King Louis XV and used this warrant to force Voltaire first into imprisonment in the Bastille and then into exile in Great Britain.
[2] Ironically, this exile proved to be of great importance to Voltaire's development as a philosopher; his exposure to the more limited constitutional monarchy of England and its emphasis on the protection of civil rights as opposed to the absolute and unrestrained rule of the French kings marked many of his later political writings.
On 7 February 1729, Guy Auguste married Yvonne Sylvie du Breil de Rays (1712–1740).
After Adélaïde died in 1805, Boniface married her cousin, another of Guy Auguste's granddaughters, Alexandrine Charlotte de Rohan-Chabot, widow of Louis Alexandre de La Rochefoucauld, 6th Duke of La Rochefoucauld.