The correct answer is: "the revolts and changes of government in France".
The development of the Enlightment principles: civil rights, social contract, suffrage, division of powers, influenced thinkers and society and triggered the French Revolution, which started in 1789 and defeated the absolut monarchy with the creation of the French Republic in 1792.
Other European countries, influenced by the same ideas, aimed to establish democratic systems and to remove the old institutions from feudalism, hence many revolutions were undertaken in Europe during the 19th century.