They're referring to the French Revolution, and then the Terror. One of the causes of the revolution was the poor being fed up with the massive wealth imbalance. An economic depression was making the masses starve in the streets, while the wealthy 1% enjoyed lives of comfort and luxury enabled by the rigged aristocratic land-owning system. So the peasants had their bloody revolution, killed a lot of the aristocrats using Dr. Guillotine's invention, and now we have modern France.

(This is, of course, a gross oversimplification of a complex historical topic. Please feel free to correct me.)