In 1774 louis 16 became the king of france. he found the treasury empty and reasons for empty treasury are
1) long years of war
2) he helped 13 colonies of USA to gain independence from britain
3) cost of maintaining extravagant courts , army , palaces, government offices etc.
so meet his expences he raised taxes and only 3rd estate had to pay taxes which included peasants, farmers, small buisnessman and lawyers and also artisans
he also increased cost of bread which was main livelihood for people of 3rd estate