Ernst II Leopold, Landgrave of Hesse-Rotenburg

He married his first cousin, Countess Eleonore of Löwenstein-Wertheim-Rochefort (1686–1753), in Frankfurt, on 9 November 1704. She was daughter of Maximilian Karl Albert, Prince of Löwenstein-Wertheim-Rochefort and his wife, Countess Maria Polyxena Khuen of Lichtenberg and Belasi (1658-1712). They had ten children:

1. Joseph, Hereditary Prince of Hesse-Rotenburg (1705–1744); married Princess Christina of Salm had issue.
2. Polyxena of Hesse-Rotenburg, Queen of Sardinia (1706–1735); married Charles Emmanuel III of Sardinia had issue.
3. Landgravine Magdalene Leopoldina of Hesse-Rotenburg (1707–1708); died in infancy.
4. Wilhelm of Hesse-Rotenburg (1708); died in infancy.
5. Sophie of Hesse-Rotenburg (1709–1711); died in infancy.
6. Franciscus Alexander of Hesse-Rotenburg (1710–1739); died unmarried.
7. Eleonore Philippina of Hesse-Rotenburg (1712–1759); married John Christian, Count Palatine of Sulzbach, no issue.
8. Landgravine Caroline of Hesse-Rotenburg (1714–1741); married Louis Henri, Duke of Bourbon, and had issue.
9. Constantine, Landgrave of Hesse-Rotenburg (1716–1778); his successor.
10. Landgravine Christine of Hesse-Rotenburg (1717–1778); married Louis Victor, Prince of Carignan, and had issue.

Through his eldest daughter, his present descendants include the claimant Duke of Parma; the pretending King of the Two Sicilies and the reigning Grand Duke of Luxembourg. His youngest daughter is also an ancestress of the above.