Princess Caroline-Mathilde of Denmark
Princess Caroline- Mathilde of Denmark( 27 April 1912 – 12 December 1995) was a daughter of Prince Harald of Denmark and granddaughter of King Frederick VIII of Denmark.
As the wife of Knud, Hereditary Prince of Denmark, she became Hereditary Princess of Denmark.
Prince Gustav of Denmark
Prince Gustav of Denmark (Christian Frederik Vilhelm Valdemar Gustav; 4 March 1887 – 5 October 1944) was the fourth and youngest son and seventh child of Frederick VIII of Denmark and his wife, Princess Louise of Sweden and Norway.
On 2 February 1935 in the Russian Orthodox Church in Copenhagen he was, together with his cousin Grand Duchess Olga Alexandrovna of Russia and her husband colonel Nikolai Kulikovsky, a godparent at the christening of Aleksander Schalburg, son of first lieutenant in the Royal Danish Life Guards Christian Frederik von Schalburg.
Prince Gustav remained unmarried and had no children.
Kaoru Hatoyama
After the elections of 2009, she became more widely known as the grandmother of Prime Minister Yukio Hatoyama and his politician brother Kunio Hatoyama.
Diana Guardato
Diana Guardato was a member of the aristocratic Patrician Guardato family, and had three children with King Ferdinand I: Diana Guardato is the 16th- Great Grandmother of His Royal Highness Albert II of Belgium, 15th- Great Grandmother of His Majesty Juan Carlos
I of Spain, 17th- Great Grandmother of Philippe of Belgium, 14th- Great Grandmother of His Majesty Manuel II of Portugal, 16th- Great Grandmother of Grand Duke Henri, as well as many others.
Tjuyu
Tjuyu( sometimes transliterated as Thuya or Thuyu) was an Egyptian noblewoman and the mother of queen Tiye, and the wife of Yuya.
She is the grandmother of Akhenaten, and great grandmother of Tutankhamun.
Louise of Sweden
Louise of Sweden (Louise Josephine Eugenie ; 31 October 1851 – 20 March 1926), was Queen of Denmark as the spouse of King Frederick VIII.
She was the only surviving child of Charles XV of Sweden and his consort, Louise of the Netherlands.
She was the mother of both King Christian X of Denmark and King Haakon VII of Norway.
Mona Hopton Bell
Mona Hopton Bell( 1867- 1940) was a British artist, best known for her portraits of civic figures.
She was the grandmother of the painter Jean H. Bell.
Anne Denman
Anne Denman( 1587–1661) was born in Olde Hall, Retford, Nottinghamshire.
Through a fortunate second marriage with Thomas Aylesbury, she became the grandmother of Lady Anne Hyde, Duchess of York and great- grandmother of Queen Mary II and Queen Anne.
Hubba bint Hulail
Hubba bint Hulail was the grandmother of Hashim ibn' Abd Manaf, thus the great- great- great- grandmother of the Islamic" Nabī"( Prophet) Muhammad ibn Abdullah.
Hannah Arnold
Hannah Arnold, also known as Hannah Waterman King, was the grandmother of Benedict Arnolds children.

Question: Who is the maternal grandmother of Prince Gustav Of Denmark?