
This passage contains a statement Qu'ils mangent de la brioche that has usually come to be attributed to Marie Antoinette; this was written in 1766, when Marie Antoinette was 10 and still 4 years away from her marriage to Louis XVI of France, and is an account of events of 1740, before she was born. It also implies the phrase had been long known before that time.
Variant: At length I recollected the thoughtless saying of a great princess, who, on being informed that the country people had no bread, replied, "Then let them eat cake!"
Source: Confessions of Jean-Jacques Rousseau (1765-1770; published 1782), Books II-VI, VI