Question: Who is Prince Albert Of Schleswig-Holstein-Sonderburg-Glücksburg's paternal grandfather?

Knowledge 1: 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. [SEP] Knowledge 2: 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.
Knowledge 1: 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. [SEP] Knowledge 2: 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.
Knowledge 1: 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. [SEP] Knowledge 2: 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.

Answer: Friedrich Wilhelm, Duke of Schleswig-Holstein-Sonderburg-Glücksburg