Joachim Ernest, Duke of Schleswig-Holstein-Sonderburg-Plön
Joachim Ernest of Schleswig-Holstein- Sonderburg- Plön( 29 August 1595 – October 5, 1671), also" Joachim Ernest of Schleswig- Holstein- Plön", was the first Duke of Schleswig- Holstein- Sonderburg- Plön, which emerged from a division of the Duchy of Schleswig- Holstein- Sonderburg.
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.
Christian August, Duke of Schleswig-Holstein-Sonderburg-Augustenburg
Christian August I, Duke of Schleswig- Holstein- Sonderburg- Augustenburg
( 4 August 1696 – 20 January 1754) was a son of Frederick William of Schleswig- Holstein- Sonderburg- Augustenburg, who was himself a son of Ernest Günther.
He served as provost of the cathedral chapter in Hamburg.
Later, he became governor of the Danish island Als, then General of the Infantry and Colonel of the royal guards in Denmark.
In 1731, Christian August I succeeded his childless uncle Ernest August.
Prince Frederick William of Schleswig-Holstein-Sonderburg-Augustenburg
Prince Frederick William of Schleswig-Holstein-Sonderburg-Augustenborg (18 November 16683 June 1714) was a member of the House of Oldenburg and a Prince of Schleswig-Holstein-Sonderburg-Augustenburg.
He was the youngest son of Duke Ernest Günther, Duke of Schleswig-Holstein-Sonderburg-Augustenburg and his wife, Auguste of Schleswig-Holstein-Sonderburg-Glücksburg.
In 1675, when his father negotiated with Count Peder Griffenfeld about a marriage with Frederick William's sister, he was promised a profitable post as provost of the Cathedral in Hamburg and governor of Als.
He was appointed as provost in Hamburg in 1676, after chairman Kielmansegge died.
When his father died in 1689, the will stated that his possessions would go to his widow, who would have the right to settle the succession.
She made a decision, which was upheld by the King in 1692.
Her eldest living son, Ernest Augustus, was excluded from the inheritance, because he had converted to Catholicism, leaving the Duchy to Frederick William, who was by then the only other surviving son.
Almost simultaneously, Frederick William was also appointed governor of Sønderborg.
However, when Ernest Augustus reverted to Lutheranism in 1695, he was appointed governor of Sønderborg, because he resided there.
Ernest Augustus was also reinstated as heir of Schleswig-Holstein-Sonderburg-Augustenburg.
Nevertheless, when Ernest Augustus died childless in 1731, Frederick William's son Christian August I would inherit the duchy.
When his mother died in 1701, Frederick William inherited Augustenborg Palace, Rumohrsgaard Manor and Evelgunde Manor.
In 1703, he purchased Avnbølgaard Manor in Sundeved.
Frederick William served as a Major General in the Danish army.
On 27 November 1694, he married Sophie Amalie, a daughter of the Chancellor, Frederick of Ahlefeldt, Count of Langeland.
She died on 24 December 1741.
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.
Frederick William II, Duke of Schleswig-Holstein-Sonderburg-Beck
Frederick William II, Duke of Schleswig-Holstein- Sonderburg- Beck( 18 June 1687 – 11 November 1749) was a Duke of Schleswig- Holstein- Sonderburg- Beck.
He served as Prussian field marshal and was appointed Governor of Berlin, but never filled the latter position.
Frederick William II was the eldest son of Duke Frederick Louis( 1653 – 1728) and his wife Louise Charlotte of Schleswig- Holstein- Sonderburg- Augustenburg( 1658 – 1740).
His siblings included Dorothea, Peter August, Charles Louis.
In 1728, Frederick William II succeeded his father as Duke of Beck.
After his death, he was succeeded by his son Frederick William III, who fell in battle in 1757.
The title was then inherited by Frederick William II's brother, Charles Louis.
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.
Ernest Günther, Duke of Schleswig-Holstein-Sonderburg-Augustenburg
Ernest Günther of Schleswig-Holstein-Sonderburg-Augustenburg (14 October 1609 – 18 January 1689) was a Duke of Schleswig-Holstein of its Sonderborg line.
He was the first to have his ducal seat in Augustenborg Palace, which he built and named in honor of his wife.
He ruled from 1647 until his death in 1689.
He was third son of Alexander, Duke of Schleswig-Holstein-Sonderburg and his wife Countess Dorothea of Schwarzburg-Sondershausen.
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.
Prince Frederick of Schleswig-Holstein-Sonderburg-Augustenburg
Prince Frederick Emil August of Schleswig-Holstein- Sonderburg- Augustenburg( Kiel, 23 August 1800 – Bayreuth, Germany, 2 July 1865), usually simply known by just his first name, Frederick," Prince of Noer", was a prince of the House of Schleswig- Holstein- Sonderburg- Augustenburg and a cadet- line descendant of the Danish royal house.
He was the second and youngest son of Louise Auguste of Denmark and Frederik Christian II, Duke of Schleswig- Holstein- Sonderburg- Augustenburg.
As such, he was close to succeed in the Danish throne.
He was the brother- in- law of King Christian VIII and nephew of King Frederik VI.
His elder brother, Christian August II, succeeded in 1814 as the Duke of Schleswig- Holstein- Sonderburg- Augustenburg.
After his second, morganatic union, he renounced the rights of succession to House of Augustenburg.
He was created Prince of Noer or Nør by Emperor Franz Joseph of Austria afterwards.
Prince Frederick died 1865 at Bayreuth.

Question: Who is the paternal grandfather of Prince Frederick William Of Schleswig-Holstein-Sonderburg-Augustenburg?
Answer: Alexander, Duke of Schleswig-Holstein-Sonderburg