The causes of the French Revolution can be broadly classified as-
1. Political causes- Absolute monarchy based on the Divine Rights of the King was prevalent in France. The Monarch lived in splendor and cared little for the welfare of the subjects. The whole administration was corrupt and high posts were often auctioned.
2. Social Causes- The French society was ridden with several inequalities. The society was divided into 3 estates. While the first 2 estates enjoyed all the privileges, the third estate lived a life of misery. The entire burden of taxation also fell almost entirely on them.
3. Economic Causes- France had been continuously involved in wars which almost ruined her economy. Louis XVI had inherited an empty treasury. He still wasted money in liberating the 13 colonies of America from the common enemy Britain. Only a fraction of the taxes could be realized as those who had to pay were too poor to pay taxes while those who could pay like the nobles, clergy etc. were exempted from it.
4. Intellectual Causes- Political thinkers like Rousseau, Voltaire, Montesquieu, Locke etc. exposed the ills of the French government and the administration which made the people aware of their rights and the duties of the government. It also propounded theories for an ideal form of government. All these caused hatred against the crown nobles and the clergy.
5. Immediate Cause- Forced by financial bankruptcy, Emperor Louis XVI was compelled to call a meeting of the Estates General in 1789 after a lapse of175 years. It was necessary to impose / increase taxes. The third estate demanded one vote for every delegate. But when the first two estates refused it the members of the third estate walked out in protest.