Princess Ernestine of Saxe-Weimar
Princess Ernestine of Saxe- Weimar- Eisenach( Ernestine Auguste Sophie; 4 January 1740 in Weimar – 10 June 1786 in Hildburghausen) was a princess of Saxe- Weimar- Eisenach and by marriage Duchess of Saxe- Hildburghausen.
Prince Hermann of Saxe-Weimar-Eisenach (1886–1964)
Prince Hermann of Saxe- Weimar- Eisenach( 14 February 1886 – 6 June 1964) was a member of the House of Saxe- Weimar- Eisenach.
He was heir to his relative William Ernest, Grand Duke of Saxe- Weimar- Eisenach until 1909, when he was disinherited of his royal status.
From that point onwards, Hermann was commonly referred to with the lesser style, Count Ostheim.
Ernest Augustus II, Duke of Saxe-Weimar-Eisenach
Ernst August II Konstantin, Duke of Saxe- Weimar- Eisenach( 2 June 1737 – 28 May 1758), was a duke of Saxe- Weimar- Eisenach.
Grand Duchess Maria Pavlovna of Russia (1786–1859)
Grand Duchess Maria Pavlovna of Russia (16 February 1786
[OS 5 February] – 23 June 1859) was the third daughter of Paul I of Russia and Sophie Dorothea of Württemberg.
She was the "Grand Duchess of Saxe-Weimar-Eisenach" by her marriage to Charles Frederick, Grand Duke of Saxe-Weimar-Eisenach.
Prince Bernhard of Saxe-Weimar-Eisenach (1878–1900)
Prince Bernhard of Saxe-Weimar-Eisenach ("Bernhard Carl Alexander Hermann Heinrich Wilhelm Oscar Friedrich Franz Peter"; 18 April 1878 – 1 October 1900) was a member of the Grand Ducal House of Saxe-Weimar-Eisenach and a Lieutenant in the Prussian Army.
He bore the titles "Prince of Saxe-Weimar-Eisenach, Duke of Saxony" with the style "Highness".
Ernest Augustus I, Duke of Saxe-Weimar-Eisenach
Ernest Augustus I, Duke of Saxe- Weimar( German:" Ernst August I"; 19 April 1688 – 19 January 1748), was a duke of Saxe- Weimar and, from 1741, of Saxe- Weimar- Eisenach.
Prince Wilhelm of Saxe-Weimar-Eisenach
Prince Wilhelm Karl Bernhard Hermann of Saxe- Weimar- Eisenach( 21 December 1853 – 15 December 1924) was a member of the House of Saxe- Weimar- Eisenach.
Princess Pauline of Saxe-Weimar-Eisenach
Princess Pauline of Saxe- Weimar- Eisenach( Pauline Ida Marie Olga Henriette Katherine; 25 July 1852, in Stuttgart – 17 May 1904, in Orte) was the wife of Charles Augustus, Hereditary Grand Duke of Saxe- Weimar- Eisenach.
She was a daughter of Prince Hermann of Saxe- Weimar- Eisenach and Princess Augusta of Württemberg.
Michael, Prince of Saxe-Weimar-Eisenach
Michael, Prince of Saxe- Weimar- Eisenach( born 15 November 1946) is the current head of the Grand Ducal House of Saxe- Weimar- Eisenach, as well as the most senior agnate of the entire House of Wettin.
Princess Marie of Saxe-Weimar-Eisenach (1808–1877)
Princess Marie of Saxe-Weimar-Eisenach (3 February 1808 in Weimar – 18 January 1877 in Berlin) was a princess of Saxe-Weimar-Eisenach, by birth, and, by marriage, a princess of Prussia.
She was the daughter of Charles Frederick, Grand Duke of Saxe-Weimar-Eisenach and Grand Duchess Maria Pavlovna of Russia.

Question: Who is the maternal grandfather of Princess Marie Of Saxe-Weimar-Eisenach (1808–1877)?
Answer: Paul I of Russia