The enlightenment period of independent thinking and the American Revolution inspired the French Revolution to begin and the editing/creating of the French constitution.
Louis XVI wanted to force aristocrats to pay taxes for the first time.
Jacobins such as Maximilien de Robespierre argued that France's king and queen needed to be executed to protect political changes; i.e. to avoid a return to absolute monarchy.
Apex: To protect the political changes made during the French Revolution