Complex sentence: Louis XVI (23 August 1754--21 January 1793) was King of France and Navarre from 1774 until 1791, after which he was subsequently King of the French from 1791 to 1792, before his deposition and execution during the French Revolution.
Split into simpler sentences: Louis XVI (23 August 1754--21 January 1793) was King of France and Navarre until 1791. Louis was subsequently King of the French from 1791 to 1792, before his deposition and execution during the French Revolution.