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.
Princess Louise Eleonore of Hohenlohe-Langenburg
Princess Luise Eleonore of Hohenlohe- Langenburg( 11 August 1763, in Langenburg – 30 April 1837, in Meiningen) was a German regent.
She was duchess of Saxe- Meiningen by marriage to George I, Duke of Saxe- Meiningen, and Regent of Saxe- Meiningen during the minority of her son from 1803 to 1821.
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.
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.
Princess Feodora of Saxe-Meiningen (1890–1972)
Princess Feodora of Saxe-Meiningen
(Feodora Karola Charlotte Marie Adelheid Auguste Mathilde; 29 May 1890 – 12 March 1972) was the eldest child of Prince Friedrich Johann of Saxe-Meiningen, a younger son of Georg II, Duke of Saxe-Meiningen, and Countess Adelaide of Lippe-Biesterfeld, a daughter of Ernst, Count of Lippe-Biesterfeld.
By marriage, she was known as Grand Duchess of Saxe-Weimar-Eisenach.
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.
Countess Adelaide of Lippe-Biesterfeld
Countess Adelaide of Lippe-Biesterfeld (22 June 1870 – 3 September 1948) was the eldest child of Ernest II, Count of Lippe-Biesterfeld and Countess Karoline of Wartensleben.
Princess Adelaide of Saxe-Meiningen
Princess Adelaide
"Adi" of Saxe-Meiningen (Adelaide Erna Caroline Marie Elisabeth; later Princess Adalbert of Prussia; 16 August 1891 – 25 April 1971) was a daughter of Prince Frederick John of Saxe-Meiningen and his wife Countess Adelaide of Lippe-Biesterfeld.
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.
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.

Question: Who is Princess Adelaide Of Saxe-Meiningen's maternal grandfather?
Answer: Ernest II, Count of Lippe-Biesterfeld