Jerrold Wexler
Jerrold Wexler( June 27, 1924 – November 10, 1992) was a noted American businessman and film producer.
He was the brother of cinematographer Haskell Wexler and the stepfather of actress Daryl Hannah.
Gerald Rudolff Ford
Gerald Rudolff Ford( December 9, 1890 – January 26, 1962) was an American businessman, creator of Ford Industries, and Republican politician who was the stepfather of U.S. President Gerald Ford and for whom Ford legally changed his name.
Princess Helena of Waldeck and Pyrmont (1899–1948)
Princess Helena of Waldeck and Pyrmont (22 December 189918 February 1948) was the only daughter of Friedrich, Prince of Waldeck and Pyrmont, last reigning Prince of Waldeck and Pyrmont, and wife of Nikolaus, Hereditary Grand Duke of Oldenburg.
Christian, Duke of Oldenburg
Christian, Duke of Oldenburg( born 1 February 1955) is the head of the Grand Ducal Family of Oldenburg.
Héctor Barrantes
Héctor Barrantes Sansoni( 1939–1990) was an Argentine polo player.
He was the stepfather of Sarah, Duchess of York.
Ameli, Duchess of Oldenburg
Princess Ameli of Löwenstein-Wertheim-Freudenberg (4 March 1923 – 26 March 2016) was the daughter of Udo, Prince of Löwenstein-Wertheim-Freudenberg, and widow of Anton-Günther, Duke of Oldenburg, the late pretender to the Grand Duchy of Oldenburg who died on September 20, 2014.
Franz Peter Knoodt
Franz Peter Knoodt (6 November 1811 – 27 January 1889) was a German Catholic theologian who was a native of Boppard.
He studied theology in Bonn und Tübingen, and later worked as a chaplain and teacher in Trier.
In 1841-43 he furthered his studies in Vienna, where he was a student of Anton Günther (1783-1863).
In 1844 he earned his doctorate of theology at Breslau, and in 1845 became a professor of philosophy at the Catholic faculty of theology at the University of Bonn.
From May 1848 to February 1849 he was a member of the Frankfurt National Assembly.
Knoodt was an ardent follower of the philosophical teachings of Anton Günther, and several years after Günther's death, he published the biographical "Anton Günther.
Eine Biographie" (1881, 2 volumes).
This work has been praised as an important source of Catholic church history.
Another noted work of Knoodt's was "Günther und Clemens; Offene Briefe" (Günther and Franz Jakob Clemens; Open Letters, 1853–54).
Both publications were placed on the Index Librorum Prohibitorum (List of Prohibited Books) by the Roman Catholic Church.
Conrad I, Count of Oldenburg
Conrad I of Oldenburg (died 1347) was the Count of Oldenburg from 1344 to 1347.
He succeeded his brother, John III of Oldenburg.
He was the son of John II of Oldenburg and Hedwig of Diepholz.
Conrad married Ingeborg, the daughter of Count Gerhard IV of Holstein-Plön.
They had four children:
Conrad I of Oldenburg is also a male-line ancestor of Queen Margrethe II of Denmark, King Harald V of Norway, and of Philip, Duke of Edinburgh, and thus of Charles, Prince of Wales, and Prince William, Duke of Cambridge.
Anton-Günther, Duke of Oldenburg
Anton-Günther, Duke of Oldenburg "(Anton-Günther Friedrich August Josias von Holstein-Gottorp, Erbgroßherzog von Oldenburg, Prinz von Lübeck, ;" 16 January 1923 – 20 September 2014) was the head of the Grand Ducal Family of Oldenburg.
He was born in Lensahn the son of Hereditary Grand Duke Nikolaus of Oldenburg (1897–1970) and his first wife Princess Helena of Waldeck and Pyrmont (1899–1948).
Duke Anton-Günther was a grandson of Frederick Augustus II, the last Grand Duke of Oldenburg, and through his mother a grandson of Friedrich, the last Prince of Waldeck and Pyrmont.
He studied for a Diplom in Forestry and succeeded as head of the Grand Ducal Family of Oldenburg upon the death of his father, the Hereditary Grand Duke, on 3 April 1970.
He died in September 2014 aged 91.
Nikolaus, Hereditary Grand Duke of Oldenburg
Nikolaus, Hereditary Grand Duke of Oldenburg( 10 August 18973 April 1970) was the eldest son of Frederick Augustus II, Grand Duke of Oldenburg, who was the last ruling Grand Duke of Oldenburg.
In 1931, Nikolaus succeeded to his father's titles and assumed the role of pretender to the Grand Duchy, until his death in 1970.

Question: Who is Anton-Günther, Duke Of Oldenburg's father?
Answer: Nikolaus, Hereditary Grand Duke of Oldenburg