​In a Nutshell:

The French Revolution (French: Révolution française; 1789–1799), was a period of radical social and political upheaval in France that had a lasting impact on French history and more broadly throughout the world. The absolute monarchy that had ruled France for centuries collapsed within three years. French society underwent an epic transformation, as feudal, aristocratic and religious privileges evaporated under a sustained assault from radical left-wing political groups, masses on the streets, and peasants in the countryside.  Old ideas about tradition and hierarchy–of monarchy, aristocracy, and religious authority–were abruptly overthrown by new Enlightenment principles of equality, citizenship and inalienable rights.