Simplify the following text for a Grade 7 native English-speaking person.
Original: Louis XVI ( 23 August 1754 â `` 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 .
Simplified: Louis XVI ( August 23 , 1754 - January 21 , 1793 ) was King of France and Navarre from 1774 to 1791 and as King of the French from 1791 to 1792 .