| Louis IX | |
|---|---|
 Portrait of Louis IX around 1780 in the Musée historique de Strasbourg | |
| Landgrave of Hesse-Darmstadt | |
| Reign | 12 October 1768 – 6 April 1790 |
| Predecessor | Louis VIII |
| Successor | Louis X |
| Born | 15 December 1719 Darmstadt |
| Died | 6 April 1790 (aged 70) Pirmasens |
| Spouses | Marie Adelaide of Cheirouze, Countess of Lemberg
(m. 1775) |
| Issue | |
| House | Hesse-Darmstadt |
| Father | Louis VIII, Landgrave of Hesse-Darmstadt |
| Mother | Countess Charlotte of Hanau-Lichtenberg |
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.[1]
Louis IX was a son of Louis VIII, Landgrave of Hesse-Darmstadt, and Charlotte of Hanau-Lichtenberg and Müntzenberg.
He was born in Darmstadt on 15 December 1719. On 12 August 1741, Louis married Caroline, daughter of Christian III, Duke of Zweibrücken. They had three sons and five daughters, including:
In 1775, Louis IX married Marie Adelaide of Cheirouze, countess of Lemberg. On 6 April 1790 Louis died in Pirmasens.
| Ancestors of Louis IX, Landgrave of Hesse-Darmstadt[2] |
|---|
