Ernst Ludwig II, Duke of Saxe-Meiningen
Ernst Ludwig II, Duke of Saxe- Meiningen( Coburg, 8 August 1709 – Meiningen, 24 February 1729), was a duke of Saxe- Meiningen.
He was the third but second surviving son of Ernst Ludwig I, Duke of Saxe- Meiningen and his first wife, Dorothea Marie of Saxe- Gotha.
The death of his older brother Josef Bernhard( 22 March 1724) made him the heir to the duchy of Saxe- Meiningen.
When his father died seven months later( 24 November 1724), Ernst Ludwig- fifteen years old- inherited the duchy along with his younger brother Karl Frederick.
Because the two princes were under age when their father died, their uncles Frederik Wilhelm and Anton Ulrich served as their guardians until 1733.
Ernst Ludwig died after reigning five years, only twenty years old and unmarried.
He was succeeded by his younger brother, Karl Frederick.
Bernhard, Prince of Saxe-Meiningen
Bernhard, Prince of Saxe- Meiningen( 30 June 1901 – 4 October 1984) was the head of the House of Saxe- Meiningen from 1946 until his death.
Dorothea Marie of Saxe-Gotha-Altenburg
Dorothea Marie of Saxe-Gotha-Altenburg (22 January 1674 – 18 April 1713) was the wife of Ernst Ludwig
I, Duke of Saxe-Meiningen.
She was the daughter of Frederick I, Duke of Saxe-Gotha-Altenburg and his first wife, Magdalena Sybille of Saxe-Weissenfels.
She married Ernst Ludwig I on the 19 September 1704.
Karl Wilhelm, Duke of Saxe-Meiningen
August Friedrich Karl Wilhelm, Duke of Saxe-Meiningen (Frankfurt, 19 November 1754 – Sonneberg, 21 July 1782), was a duke of Saxe-Meiningen.
Karl Friedrich, Duke of Saxe-Meiningen
Karl Friedrich, Duke of Saxe-Meiningen (Meiningen, 18 July 1712 – Meiningen, 28 March 1743), was a duke of Saxe-Meiningen.
He was the fourth but third surviving son of Ernst Ludwig
I, Duke of Saxe-Meiningen and his first wife, Dorothea Marie of Saxe-Gotha-Altenburg.
Karl Friedrich inherited the duchy of Saxe-Meiningen when his father died in 1724, along with his older brother, Ernst Ludwig II, under the guardianship of his uncles Frederick Wilhelm and Anton Ulrich until 1733.
When his older brother died unmarried in 1729, Karl Frederick ruled alone until his death.
Like his brother, he never married, and, after his death, was succeeded by his uncle, Friedrich Wilhelm.
Princess Charlotte of Saxe-Meiningen
Princess Charlotte of Saxe- Meiningen( 11 September 1751, Frankfurt am Main, Free Imperial City of Frankfurt, Holy Roman Empire – 25 April 1827, Genoa, Kingdom of Sardinia) was a member of the House of Saxe- Meiningen and a Princess of Saxe- Meiningen by birth and a member of the House of Saxe- Gotha- Altenburg and Duchess consort of Saxe- Gotha- Altenburg through her marriage to Ernest II, Duke of Saxe- Gotha- Altenburg.
Friedrich Wilhelm, Duke of Saxe-Meiningen
Friedrich Wilhelm, Duke of Saxe- Meiningen( 16 February 1679 in Ichtershausen – 10 March 1746 in Meiningen), was a duke of Saxe- Meiningen.
Georg, Prince of Saxe-Meiningen
Georg, Prince of Saxe- Meiningen( 11 October 1892 – 6 January 1946) was the head of the house of Saxe- Meiningen from 1941 until his death.
Bernhard III, Duke of Saxe-Meiningen
Bernhard III, Duke of Saxe- Meiningen( 1 April 1851 – 16 January 1928), was the last reigning duke of Saxe- Meiningen.
Anton Ulrich, Duke of Saxe-Meiningen
Anton Ulrich, Duke of Saxe-Meiningen (Meiningen, 22 October 1687 – Frankfurt, 27 January 1763), was Duke of Saxe-Meiningen from 1746 to 1763.

Question: Who is Karl Friedrich, Duke Of Saxe-Meiningen's maternal grandfather?