Louis_IX,_Landgrave_of_Hesse-Darmstadt

Louis IX of Hesse-Darmstadt (German: Ludwig) (15 December 1719 – 6 April 1790) was the reigning Landgrave of Hesse-Darmstadt from 1768 to 1790.
Louis IX and his wife Countess Palatine Caroline of Zweibrücken became the most recent common ancestors of all current hereditary European monarchs on 8 September 2022 after Queen Elizabeth II of the United Kingdom, who was not a descendant, died and her son, Charles III, a descendant through his father, became king.