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.
Kaya Alp
Kaya Alp was, according to Ottoman tradition, the son of Kızıl Buğa and the father of Suleyman Shah, who was, in turn, the grandfather of Ertuğrul, and the great grandfather of the Ottoman Empire founder, Osman I.
John Westley
Rev. John Westley( 1636 – 78) was an English nonconformist minister.
He was the grandfather of John Wesley( founder of Methodism).
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.
Princess Feodora of Denmark
Princess Feodora of Denmark( Feodora Louise Caroline- Mathilde Viktoria Alexandra Frederikke Johanne)
( 3 July 1910 – 17 March 1975) was a Danish princess as a daughter of Prince Harald of Denmark and granddaughter of Frederick VIII of Denmark.
As the wife of Prince Christian of Schaumburg- Lippe she became a Princess of Schaumburg- Lippe by marriage.
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.
Abd al-Muttalib
Abd al- Muttalib Shaybah ibn Hashim( c. 497 – 578) was the grandfather of Islamic prophet Muhammad.
Francis of Denmark
Francis of Denmark( 15 July 1497 – 1 April 1511), was a prince of Denmark, Norway and Sweden, the youngest son of King John of Denmark and Christina of Saxony.
Lyon Cohen
Lyon Cohen( 1868–1937) was a Polish- born Canadian businessman and a philanthropist.
He was the grandfather of singer/ poet Leonard Cohen.
Prithvipati Shah
Prithvipati Shah( ?–1716) was the king of the Gorkha Kingdom in the Indian subcontinent, present- day Nepal.
He was the grandfather of Nara Bhupal Shah.

Question: Who is Prince Gustav Of Denmark's maternal grandfather?
Answer: Charles XV of Sweden