Georg Donatus, Hereditary Grand Duke of Hesse
Prince Georg Donatus, Hereditary Grand Duke of Hesse ("Georg Donatus Wilhelm Nikolaus Eduard Heinrich Karl", 8 November 1906 – 16 November 1937) was the first child of Ernest Louis, Grand Duke of Hesse and his second wife, Princess Eleonore of Solms-Hohensolms-Lich.
He was a nephew of Empress Alexandra, wife of Emperor Nicholas II of Russia.
Louis I, Grand Duke of Hesse
Louis I, Grand Duke of Hesse( 14 June 1753 in Prenzlau – 6 April 1830 in Darmstadt) was" Landgrave of Hesse- Darmstadt"( as" Louis X") and later the first" Grand Duke of Hesse and by Rhine".
Prince Charles of Hesse and by Rhine
Prince Charles of Hesse and by Rhine (23 April 1809 - 20 March 1877) was the second surviving son of Louis II, Grand Duke of Hesse and Wilhelmine of Baden.
Margaret, Princess of Hesse and by Rhine
Margaret, Princess of Hesse and by Rhine( born Margaret Campbell Geddes, 18 March 1913 – 26 January 1997) was the wife of Louis, Prince of Hesse and by Rhine, the last prince of the House of Hesse- Darmstadt.
Born in Ireland, she became a noted art patron in her adopted homeland of Germany.
Princess Irene of Hesse and by Rhine
Princess Irene of Hesse and by Rhine(" Irene Luise Marie Anne, Princess of Hesse and by Rhine", 11 July 1866 – 11 November 1953) was the third child and third daughter of Princess Alice of the United Kingdom and Louis IV, Grand Duke of Hesse and by Rhine.
Her maternal grandparents were Queen Victoria and Prince Albert of Saxe- Coburg and Gotha.
Her paternal grandparents were Prince Charles of Hesse and by Rhine and Princess Elizabeth of Prussia.
She was the wife of Prince Henry of Prussia, a younger brother of Wilhelm II, German Emperor and her first cousin.
The SS" Prinzessin Irene", a liner of the North German Lloyd was named after her.
Her siblings included Princess Victoria of Hesse and by Rhine, wife of Prince Louis of Battenberg, Grand Duchess Elizabeth Feodorovna of Russia, wife of Grand Duke Sergei Alexandrovich of Russia, Ernest Louis, Grand Duke of Hesse and by Rhine, and Empress Alexandra Feodorovna of Russia, wife of Tsar Nicholas II of Russia.
Like her younger sister, the empress, Irene was a carrier of the hemophilia gene, and Irene would lose her sisters Alix and Elisabeth in Russia to the Bolsheviks.
Princess Johanna of Hesse and by Rhine
Princess Johanna Marina Eleonore of Hesse and by Rhine
(Johanna Marina Eleonore Prinzessin und
Landgräfin von Hessen; 20 September 1936 – 14 June 1939) was a German Hessian and Rhenish child princess, the third child and only daughter of Georg Donatus, Hereditary Grand Duke of Hesse, and Princess Cecilie of Greece and Denmark.
She was orphaned at the age of fourteen months when her parents, older brothers Ludwig and Alexander and paternal grandmother Eleonore were killed in a plane crash on their way to a family wedding in London.
The remains of her unnamed stillborn baby brother were also found among the wreckage.
After the accident, her paternal uncle Ludwig married his bride Margaret Campbell Geddes.
The couple adopted Johanna, their orphaned niece, and planned to raise her as their own daughter, but she developed meningitis and died twenty months later at the age of two and a half.
Her maternal grandmother, Princess Alice of Battenberg, said later that the unconscious Johanna so closely resembled her mother at the same age that it felt like losing her daughter Cecilie all over again.
Following Johanna's death, she was buried with her parents and brothers at the Rosenhöhe.
Prince Friedrich of Hesse and by Rhine
Prince Friedrich of Hesse and by Rhine( Friedrich Wilhelm August Victor Leopold Ludwig; 7 October 1870 – 29 May 1873) was the haemophiliac second son of Louis IV, Grand Duke of Hesse, and Princess Alice of the United Kingdom, one of the daughters of Queen Victoria.
He was also a maternal great- uncle of Prince Philip, Duke of Edinburgh through his eldest sister Princess Victoria of Hesse and by Rhine.
Louis III, Grand Duke of Hesse
Louis III, Grand Duke of Hesse and by Rhine( 9 June 1806, Darmstadt – 13 June 1877, Seeheim) was Grand Duke of Hesse and by Rhine from 1848 until his death in 1877.
Princess Louise of Hesse-Darmstadt (1761–1829)
Louise Henriette Karoline of Hesse- Darmstadt( 15 February 1761 – 24 October 1829), was the first Grand Duchess of Hesse and by Rhine by marriage.
Louis II, Grand Duke of Hesse
Louis II( 26 December 1777 – 16 June 1848) was Grand Duke of Hesse and by Rhine from 6 April 1830 until 5 March 1848, resigning during the German Revolution of 1848.
He was the son of Louis I, Grand Duke of Hesse, and Princess Louise of Hesse- Darmstadt.

Question: Who is Princess Johanna Of Hesse And By Rhine's paternal grandfather?