What was the Estates General? Why was it not convened by the Monarchs since 1614?

The Estates General was an old representative Council of France comprising the three Estates, i.e., the clergy, the nobility and the bourgeoisie.

The Estates General had not been convened by the Monarchs for a long time so that they could raise taxes and spend public money without any hassles. Also, the clergy and the nobility were against sitting with the Third state(the bourgeoisie).