Were Louis XVI of France and Napoleon alive at the same time?
Yes. Louis XVI of France and Napoleon were alive at the same time for 23 years, from 1769 to 1793.
Louis XVI of France was 14 when Napoleon was born.
Napoleon was 23 when Louis XVI of France died, aged 38.
Louis XVI of France
King of France and Navarre from 1774 to 1791, then King of the French from 1791 to 1792
Born 23 August 1754 · died 21 January 1793, aged 38
Napoleon
French military leader, French Emperor 1804–1814 and again in 1815
Born 15 August 1769 · died 5 May 1821, aged 51