Question: Who is Frederick Ix Of Denmark's father-in-law?

Ingrid of Sweden
Ingrid of Sweden
(Ingrid Victoria Sofia Louise Margareta; 28 March 1910 – 7 November 2000) was Queen of Denmark from 1947 until 1972 as the wife of King Frederick IX.
Born into the House of Bernadotte, she was the daughter of King Gustaf VI Adolf of Sweden and his first wife, Princess Margaret of Connaught.
In 1935 she married Crown Prince Frederick of Denmark and they had three daughters, Margrethe, the present Queen of Denmark, Benedikte, now a Princess of Sayn-Wittgenstein-Berleburg, and Anne-Marie, the former Greek queen.
In 1947, her husband became king on his father's death.
As queen, Ingrid reformed the traditions of Danish court life, abolished many old-fashioned customs at court and created a more relaxed atmosphere at official receptions.
King Frederick IX died in 1972, and Ingrid's daughter Margrethe became queen.
She was also a paternal aunt of the present Swedish monarch, King Carl XVI Gustaf.
Louise of Hesse-Kassel
Louise of Hesse-Kassel (7 September 1817 – 29 September 1898) was Queen of Denmark by marriage to King Christian IX of Denmark.
Princess Louise of Denmark (1750–1831)
Princess Louise of Denmark and Norway( 20 January 1750 – 12 January 1831) was born to Frederick V of Denmark and Louise of Great Britain.
Her eldest daughter, Marie of Hesse- Kassel, was the wife of Frederick VI of Denmark.
Frederick IX of Denmark
Frederick IX (Christian Frederik Franz Michael Carl Valdemar Georg; 11 March 1899 – 14 January 1972) was King of Denmark from 1947 to 1972.
Born into the House of Glücksburg, Frederick was the elder son of King Christian X and Queen Alexandrine of Denmark.
He became crown prince when his father succeeded as king in 1912.
As a young man, he was educated at the Royal Danish Naval Academy.
In 1935, he was married to Princess Ingrid of Sweden and they had three daughters, Margrethe, Benedikte and Anne-Marie.
During Nazi Germany's occupation of Denmark, Frederick acted as regent on behalf of his father from 1942 until 1943.
Frederick became king on his father's death in early 1947.
During Frederick IX's reign Danish society changed rapidly, the welfare state was expanded and, as a consequence of the booming economy of the 1960s, women entered the labour market.
The modernization brought new demands on the monarchy and Frederick's role as a constitutional monarch.
Frederick IX died in 1972, and was succeeded by his eldest daughter, Queen Margrethe II.
Frederick IX, Margrave of Brandenburg
Frederick IX of Brandenburg( 22 March 1588 in Cölln – 19 May 1611 in Sonnenburg, Prussia( now Słońsk, Poland)) was a Margrave of Brandenburg.
Margrethe II of Denmark
Margrethe II( full name:" Margrethe Alexandrine Þórhildur Ingrid"; born 16 April 1940) is Queen of Denmark, as well as the supreme authority of the Church of Denmark and commander- in- chief of the Danish Defence.
Born into the House of Glücksburg, a royal house with origins in northern Germany, she was the eldest child of Frederick IX of Denmark and Ingrid of Sweden.
She became heir presumptive to her father in 1953, when a constitutional amendment allowed women to inherit the throne.
Margrethe succeeded her father upon his death on 14 January 1972.
On her accession, she became the first female monarch of Denmark since Margrethe I, ruler of the Scandinavian kingdoms in 1375 – 1412 during the Kalmar Union.
In 1967, she married Henri de Laborde de Monpezat, with whom she has two sons: Crown Prince Frederik and Prince Joachim.
She has been on the Danish throne for years, becoming the second- longest- reigning Danish monarch after her ancestor Christian IV.
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.
Queen Anne-Marie of Greece
Queen Anne- Marie of Greece, RE( born Princess Anne- Marie of Denmark on 30 August 1946) is the wife of King Constantine II, who reigned from 1964 until 1973.
Anne- Marie is the youngest daughter of King Frederick IX of Denmark and his wife Ingrid of Sweden.
She is the youngest sister of the reigning Queen Margrethe II of Denmark and cousin of the reigning King Carl XVI Gustaf of Sweden.
Barthold A. Butenschøn Sr.
Hans Barthold Andresen Butenschøn( 27 December 1877 – 28 November 1971) was a Norwegian businessperson.
He was born in Kristiania as a son of Nils August Andresen Butenschøn and Hanna Butenschøn, and grandson of Nicolay Andresen.
Together with Mabel Anette Plahte( 1877 – 1973, a daughter of Frithjof M. Plahte) he had the son Hans Barthold Andresen Butenschøn Jr. and was through him the father- in- law of Ragnhild Butenschøn and grandfather of Peter Butenschøn.
Through his daughter Marie Claudine he was the father- in- law of Joakim Lehmkuhl, through his daughter Mabel Anette he was the father- in- law of Harald Astrup( a son of Sigurd Astrup) and through his daughter Nini Augusta he was the father- in- law of Ernst Torp.
He took commerce school and agricultural school.
He was hired in the family company N. A. Andresen& Co, and became a co-owner in 1910.
He eventually became chief executive officer.
The bank changed its name to Andresens Bank in 1913 and merged with Bergens Kreditbank in 1920.
The merger was dissolved later in the 1920s.
He was also a landowner, owning Nedre Skøyen farm and a lot of land in Enebakk.
He chaired the board of Nydalens Compagnie from 1926, having not been a board member before that.
He also chaired the supervisory council of Forsikringsselskapet Viking and Nedre Glommen salgsforening, and was a supervisory council member of Filharmonisk Selskap.
He was a member of the gentlemen's club SK Fram since 1890, and was proclaimed a lifetime member in 1964.
He was buried in Enebakk.
Ogawa Mataji
Viscount was a general in the early Imperial Japanese Army.
He was also the father- in- law of Field Marshal Gen Sugiyama.

Answer: Gustaf VI Adolf of Sweden