Karl, Duke of Schleswig-Holstein-Sonderburg-Glücksburg
Karl of Schleswig -Holstein- Sonderburg- Glücksburg( 30 September 1813 at Gottorp in Schleswig, Duchy of Schleswig – 24 October 1878 at Luisenlund, Glücksburg, in Schleswig- Holstein, Prussia) was the second Duke of Schleswig- Holstein- Sonderburg- Glücksburg.
Karl was the eldest son of Friedrich Wilhelm, Duke of Schleswig- Holstein- Sonderburg- Glücksburg and Princess Louise Caroline of Hesse- Kassel and an elder brother of Christian IX of Denmark.
Karl became Duke of Schleswig- Holstein- Sonderburg- Glücksburg upon his father's death on 27 February 1831.
Princess Ortrud of Schleswig-Holstein-Sonderburg-Glücksburg
Princess Ortrud of Schleswig- Holstein- Sonderburg- Glücksburg(" Ortrud Prinzessin zu Schleswig- Holstein- Sonderburg- Glücksburg"; Full given names:" Ortrud Bertha Adelheid Hedwig"),( 19 December 1925 – 6 February 1980) was a Princess and a member of the House of Schleswig- Holstein- Sonderburg- Glücksburg by birth, and through her marriage to Prince Ernest Augustus of Hanover( 1914 – 1987), a member of the House of Hanover.
Prince Julius of Schleswig-Holstein-Sonderburg-Glücksburg
Prince Julius of Schleswig-Holstein- Sonderburg- Glücksburg( 14 October 1824, Gottorp, Schleswig, Duchy of Schleswig – 1 June 1903, Itzehoe, Schleswig- Holstein, Germany) was the eighth of the ten children of Friedrich Wilhelm, Duke of Schleswig- Holstein- Sonderburg- Glücksburg and Princess Louise Caroline of Hesse- Kassel.
Prince Albert of Schleswig-Holstein-Sonderburg-Glücksburg
Prince Albert of Schleswig-Holstein-Sonderburg-Glücksburg (15 March 1863, Kiel, Duchy of Holstein – 23 April 1948, Glücksburg, Schleswig-Holstein, Germany) was the fifth and youngest child of Friedrich, Duke of Schleswig-Holstein-Sonderburg-Glücksburg and his wife Princess Adelheid of Schaumburg-Lippe and was a nephew of Christian IX of Denmark.
Albert was the grandfather of Ernst August, Prince of Hanover through his daughter Princess Ortrud of Schleswig-Holstein-Sonderburg-Glücksburg.
Albert was recognized by a family compact of 1904 as possessing rights of succession to the Grand Duchy of Oldenburg in the event of the extinction of the reigning Grand Ducal line.
Friedrich Ferdinand, Duke of Schleswig-Holstein
Friedrich Ferdinand of Schleswig- Holstein- Sonderburg- Glücksburg( 12 October 1855 – 21 January 1934) was the fourth Duke of Schleswig- Holstein- Sonderburg- Glücksburg and became Duke of Schleswig- Holstein in 1931.
Princess Alexandra Victoria of Schleswig-Holstein-Sonderburg-Glücksburg
Princess Alexandra Victoria of Schleswig-Holstein- Sonderburg- Glücksburg( 21 April 1887 – 15 April 1957) was a daughter of Friedrich Ferdinand, Duke of Schleswig- Holstein and his wife Princess Karoline Mathilde of Schleswig- Holstein- Sonderburg- Augustenburg.
Augusta of Schleswig-Holstein-Sonderburg-Glücksburg
Princess Augusta of Schleswig-Holstein- Sonderburg- Glücksburg( 27 June 1633 – 26 May 1701) was a Danish- German princess of the senior Glücksburg line of the Duke of Schleswig- Holstein.
She was the first Duchess of Augustenborg by marriage.
Augustenborg palace, and as a consequence the nearby town, were named in honor of her.
The great- granddaughter of king Christian III of Denmark, she was the third daughter, eighth by birth, of Philip, Duke of Schleswig- Holstein- Sonderburg- Glücksburg and Princess Sophia Hedwig of Saxe- Lauenburg.
She was sister of Sophia Dorothea of Schleswig- Holstein- Sonderburg- Glücksburg
Princess Karoline Mathilde of Schleswig-Holstein-Sonderburg-Glücksburg
Princess Karoline Mathilde of Schleswig- Holstein- Sonderburg- Glücksburg( Viktoria- Irene Adelheid Auguste Alberta Feodora Karoline Mathilde of Schleswig -Holstein- Sonderburg- Glücksburg; 11 May 1894 – 28 January 1972) was a member of the House of Schleswig- Holstein- Sonderburg- Glücksburg and Princess of Schleswig- Holstein- Sonderburg- Glücksburg by birth and a member of the House of Solms Baruth and Countess of Solms Baruth through her marriage to Count Hans of Solms- Baruth.
Friedrich, Duke of Schleswig-Holstein-Sonderburg-Glücksburg
Friedrich of Schleswig-Holstein-Sonderburg-Glücksburg (23 October 1814 in Schleswig, Duchy of Schleswig – 27 November 1885 in Luisenlund, Schleswig-Holstein, Prussia) was the third Duke of Schleswig-Holstein-Sonderburg-Glücksburg.
Friedrich was the second-eldest son of Friedrich Wilhelm, Duke of Schleswig-Holstein-Sonderburg-Glücksburg and Princess Louise Caroline of Hesse-Kassel and an elder brother of Christian IX of Denmark.
Friedrich inherited the title of Duke of Schleswig-Holstein-Sonderburg-Glücksburg upon his childless brother Karl's death on 14 October 1878.
Friedrich Wilhelm, Duke of Schleswig-Holstein-Sonderburg-Glücksburg
Friedrich Wilhelm, Duke of Schleswig-Holstein-Sonderburg-Glücksburg (4 January 1785 – 17 February 1831) inherited the title of Duke of Schleswig-Holstein-Sonderburg-Beck in 1816.
He subsequently changed his title to Duke of Schleswig-Holstein-Sonderburg-Glücksburg in 1825 and founded a line that includes the Royal Houses of Denmark, Greece, Norway, and the Commonwealth realms.

Question: Who is Prince Albert Of Schleswig-Holstein-Sonderburg-Glücksburg's paternal grandfather?
Answer: Friedrich Wilhelm, Duke of Schleswig-Holstein-Sonderburg-Glücksburg