How Long Did the Constitutional Monarchy Established in 1791 Last?

The constitutional monarchy established by the French Constitution of 1791 lasted for less than one year—from September 1791 to August 1792. Although it aimed to balance power between the king and the elected Legislative Assembly, tensions quickly escalated. King Louis XVI secretly opposed the revolution’s reforms and tried to flee France with his family in June 1791. 

His capture at Varennes shattered public trust. By 1792, France was at war with Austria and Prussia. Many revolutionaries believed the king was conspiring with foreign monarchs to suppress the revolution. Riots erupted in Paris, and revolutionary groups demanded the end of monarchy. On August 10, 1792, insurgents stormed the Tuileries Palace, overthrowing royal authority. 

The National Assembly then suspended the king and called for elections to form a National Convention, which declared France a republic on September 21, 1792. Louis XVI was later executed in January 1793. 

Though short-lived, the 1791 constitutional monarchy represented France’s first attempt at democratic reform and the separation of powers. It collapsed due to lack of trust, war pressures, and social unrest, paving the way for a radical phase of the French Revolution and the birth of the First Republic.