Louis XVI (23 August 1754 -- 21 January 1793) ruled as King of France and Navarre from 1774 until 1791, and then as King of the French from 1791 to 1792. Suspended and arrested as part of the insurrection of 10 August during the French Revolution, he was tried by the National Convention, found guilty of high treason, and executed by guillotine on 21 January 1793 as a desacralized French citizen known as "Citoyen Louis Capet". He is the only king of France ever to be executed.
Although Louis XVI was beloved at first, his indecisiveness and conservatism led some elements of the people of France to eventually view him as a symbol of the perceived tyranny of the Ancien Régime and gave him the nickname Oncle Louis ("Uncle Louis"). After the abolition of the monarchy in 1792, the new republican government gave him the surname Capet, a nickname in reference to Hugh Capet, the founder of the Capetian dynasty -- which the revolutionaries interpreted as a family name.