Frederick Henry Louis, was a Prince of Prussia and the younger brother of Frederick the Great, was King of Prussia from 1740 until which year, the longest reign of any Hohenzollern king?
Prince Henry of Prussia (1726–1802): Frederick Henry Louis (German: "Friedrich Heinrich Ludwig" ) (18 January 1726 – 3 August 1802), commonly known as Henry ("Heinrich "), was a Prince of Prussia and the younger brother of Frederick the Great. Frederick the Great: Frederick II (German: "Friedrich" ; 24 January 171217 August 1786) was King of Prussia from 1740 until 1786, the longest reign of any Hohenzollern king.
1786