After the 3rd estate voted to end the Noble's privileges the Declaration of the Rights of Man and of the Citizen said all men were free and equal, all men had natural rights, government must protect natural rights, freedom of religion, people should be taxed based on ability to pay, but it gave no rights to women.
Thousands of women marched to the palace of Versailles demanding bread! They forced Louis XVI and Marie to move to Paris under house arrest. They try to secretly escape Austria but are caught and are returned to Paris as prisoners. People now completely distrust Louis XVI and this is the end to monarchy.
Because of this failed escape that people found distrustful, France declares war on Austria fearing the queen's family would try to reinstate Louis XVI. Louis XVI's letters to foreign leaders was used to make the royal family look like traitors!