Question: Who is Catherine I, Latin Empress's father-in-law?

John Adams (merchant)
John Adams( 1672 or 1673 – 1745) was an American- born Canadian merchant and member of the Nova Scotia Council.
He was the father- in- law of Henry Newton( politician).
Peter Burroughs
Peter Burroughs( born 27 January 1947) is a British television and film actor, the director of Willow Management.
He is the father- in- law of actor and TV presenter Warwick Davis.
Catherine I, Latin Empress
Catherine I, also Catherine of Courtenay (25 November 1274 – 11 October 1307), was the recognised Latin Empress of Constantinople from 1283 to 1307, although she lived in exile and only held authority over Crusader States in Greece.
In 1301, she became the second wife of Charles of Valois, by whom she had one son and three daughters; the eldest of these, Catherine II of Valois, Princess of Achaea succeeded her as titular empress.
Charles, Count of Valois
Charles of Valois (12 March 1270 – 16 December 1325), the third son of Philip III of France and Isabella of Aragon, was a member of the House of Capet and founder of the House of Valois, whose rule over France would start in 1328.
Charles ruled several principalities.
He held in appanage the counties of Valois, Alençon and Perche.
Through his marriage to Margaret of Anjou, he became Count of Anjou and Maine.
Through his marriage to Catherine I, titular empress of the Latin Empire, he was titular Latin Emperor of Constantinople from 1301–1307, although he ruled from exile and only had authority over Crusader States in Greece.
The grandson of Louis IX of France, Charles of Valois was a son, brother, brother-in-law and son-in-law of kings or queens (of France, Navarre, England and Naples).
His descendants, the House of Valois, would become the royal house of France three years after his death, beginning with his son Philip VI of France.
Alice of Courtenay
Alice of Courtenay, Countess of Angoulême( 1160 – 12 February 1218) was a French noblewoman of the House of Courtenay.
Her father was Peter I of Courtenay and her brother was Peter II of Courtenay, Latin Emperor of Constantinople.
Alice married twice; by her second husband, Aymer Taillefer, Count of Angoulême, she was the mother of Isabella of Angoulême, who was Queen consort of England, as the wife of King John.
She is also known as Alix de Courtenay.
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.
Beatrice of Sicily, Latin Empress
Beatrice of Sicily (1252 – 17 November/12 December 1275) was titular Latin Empress as the wife of Philip of Courtenay.
Her parents were Charles I of Sicily and Beatrice of Provence.
Under the Treaty of Viterbo (27 May 1267), Baldwin II of Courtenay transferred much of the rights to the Latin Empire to Charles I. Charles was to be confirmed in possession of Corfu and some cities in Albania.
He was also given suzerainty over the Principality of Achaea and sovereignty of the Aegean Islands, excepting those held by Venice and Lesbos, Chios, Samos, and Amorgos.
The same treaty arranged the marriage of Philip of Courtenay, heir apparent to the Latin Empire, and Beatrice, second daughter of Charles.
If the marriage was childless, Philip's rights would be inherited by Charles I. Beatrice was approximately fifteen-years-old at the time of her betrothal.
On 15 October 1273, Beatrice and Philip were married in Foggia.
The bride was twenty-one-years old and the groom thirty.
Her father-in-law died days later.
Philip was proclaimed emperor with Beatrice as empress.
The marriage was harmonious and produced a daughter, Catherine I of Courtenay, born on 25 November 1274.
Beatrice died in late 1275 after a short illness.
Ludwig von Westphalen
Johann Ludwig von Westphalen( 11 July 1770 – 3 March 1842) was a liberal Prussian civil servant and the father- in- law of Karl Marx.
James Armour (Master mason)
James Armour (15 January 1730 – 20 September 1798) was a master mason and father of Jean Armour, and therefore the father-in-law of the poet Robert Burns.
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: Philip III of France