Ludwig IX. von Hessen-Darmstadt, Landgraf von Hessen-Darmstadt, was born 16 December 1719 in Darmstadt, Hesse, Germany to Ludwig VIII. von Hessen-Darmstadt (1691-1768) and Charlotte von Hanau-Lichtenberg (1700-1726) and died 6 April 1790 Pirmasens, Rhineland-Palatinate, Germany of unspecified causes. He married Henriette Karoline von Pfalz-Zweibrücken (1721-1774) 12 August 1741 in Zweibrücken. Charlemagne (747-814)/s, Henry II of England (1133-1189)/s, Hugh Capet (c940-996)/s.