The King and Queen were wasting the money they didn't even have while France was going through bankruptcy. They were not doing a good job at taking care of their people.
After the people were outraged with the King, they were looking to kill them. The Nobles all ran away and told the King that he should run away. They decided to run away to Austria who France was in a war with. So they disguised themselves as peasants, but were recognized by a postman.
After being recognised they were automatically captured by the mob of people . Once they were captured King Louis was executed by the Guillotine. Marie would soon suffer the same fate as her late husband did. And thus ended the ruling of King Louis and Marie.