Louis XVI became king in 1774 and inherited a monarchy strained by debt, unequal taxation, and institutional conflict. He initially supported ministers who proposed economic and fiscal changes, including Turgot and later Necker, but opposition from privileged groups and the court helped undermine reforms. His government allied with the American revolutionaries in 1778. French military and naval assistance contributed decisively to American independence, while the expense further weakened the monarchy's finances.

Attempts to widen taxation encountered resistance from the Assembly of Notables and the parlements. Unable to resolve the crisis, Louis summoned the Estates-General, which met in May 1789. Disputes over representation and voting led the Third Estate to declare itself a National Assembly. Royal hesitation, troop movements, and dismissal of Necker intensified mistrust. The fall of the Bastille and uprisings in the countryside forced acceptance of major changes. In October a crowd brought the royal family from Versailles to Paris, placing them under closer public scrutiny.

Louis accepted some revolutionary measures but remained deeply troubled by the loss of royal authority and changes imposed on the Catholic Church. His apparent cooperation alternated with efforts to seek assistance and recover freedom of action. The royal family's attempted flight in June 1791 ended at Varennes and severely damaged confidence in him. Later that year he accepted a constitution establishing a limited monarchy. His use of the veto and disputes over war and religious policy kept him at odds with many revolutionaries, who increasingly suspected collaboration with foreign enemies.

France's declaration of war in 1792 and military setbacks sharpened the crisis. On August 10 insurgents stormed the Tuileries, and the monarchy was suspended. The National Convention abolished kingship in September and tried Louis as a citizen for offenses against the nation. Documents and his conduct during the Revolution formed part of the prosecution, though the proceedings were inseparable from a struggle over the republic's future. Convicted and sentenced to death by close and contested votes, he was guillotined in Paris on January 21, 1793. His rule ended the Bourbon monarchy of the Old Regime in France. Assessments of his career weigh personal indecision and political misjudgment against a structural crisis that successive ministers had failed to overcome.