They had that meeting because the French government was having financial problems. The third estate took things into their own hands. It determined a person's legal rights and status.
When the 3rd Estate became the 'National Assembly' they took an oath in the tennis court. They talked about the problems they were facing.
Bastille was attacked by an angry mob. It became one of the defining moments in the Revolution that followed.
They killed 40,000 people that were suspected of being traitors, were beheaded. Maximilien Robespierre was the leader of the Reign of Terror. The Reign of Terror famously used the guillotine to behead victims. It was also used to behead Louis XVI and Marie Antoinette.
He crowned himself emperor so he can have all the power. He defeated most of the wars he fought. He was sent to Elba to learn from his mistakes.
It was a meeting of ambassadors of European states and was held in Vienna. It was made up of four European powers that had defeated Napoleon. It was made to maintain peace between great powers.