The clergy people were a part of the 1st estate of the french society. They had an exemption from paying taxes and extracted the share of taxes called 'tithes' and 'taille' from all members of the 3rd estate.
The nobility comes under the 2nd estate of French society. The nobility consists of the members of the Royal Family like the kings, queens, etc. Even they had an exemption from paying taxes and enjoyed feudal privileges. These included feudal dues which they extracted from the peasants.
The 3rd estate of french society consisted of the common people like merchants, lawyers, peasants, servants, landless laborers, etc. burden of financing activities of the state through taxes was borne by the third estate alone. And taxes kept increasing due to some or the other reason. Necessary action was to be taken.
On 5 May 1789, Louis XVI called together an assembly of the Estates-General to pass proposals for new taxes. The 1st and 2nd estates and 300 representatives each. The 600 representatives of the 3rd estate had to stand at the back, which consisted of more prosperous and educated people. Few of the 3rd estate people were denied entry however their grievances were written in 40,000 letters.
On 20 June they assembled in the hall of an indoor tennis court on the grounds of Versailles. They declared themselves as a National Assembly and swore not to disperse till they had drafted a constitution for France that would limit the powers of the monarch.
The price of bread rose, and often bakers exploited the situation and hoarded supplies. After spending hours in long queues at the bakery, crowds of angry women stormed into the shops. At the same time, the king ordered troops to move into Paris. On 14th July, the agitated crowd stormed and destroyed the Bastille.