Question: Who is Maria-Irene Palaiologina's father-in-law?

Knowledge 1: Maria-Irene Palaiologina
Irene Palaiologina (Irina; Ειρήνη Παλαιολογίνα) (1327 - after 1356) was a Byzantine princess and Bulgarian empress consort.She was also known as Maria Palaiologina (Μαρία Παλαιολογίνα).Her parents were Andronikos III Palaiologos and Anna of Savoy, whilst her siblings were John V Palaiologos and Michael Palaiologos.She married in 1336 Tsar Michael Asen IV of Bulgaria.Nothing else is known about her, except that she was an Orthodox Christian. [SEP] Knowledge 2: Michael Asen IV of Bulgaria
Michail Asen  (c. 1322–1355) was the eldest son of Ivan Alexander of Bulgaria from his marriage with Theodora of Wallachia.After his father acceded to the throne in 1331, the young prince was proclaimed co-Emperor.He was to succeed his father under the name Michael IV Asen.The heir to the throne was the pride of the royal family and was said to possess "all virtues".He married Maria, renamed Irina, the daughter of Andronikos III Palaiologos.In 1354–1355 the Ottoman Turks invaded Bulgaria and headed towards Plovdiv and Sofia.It is mentioned in an anonymous Bulgarian chronicle that Michail Asen gathered the Bulgarians and engaged the Turks near Sofia.The Bulgarians were defeated and suffered heavy casualties including Michail himself.But the battle was not in vain: the Ottomans failed to capture the cities and did not attack the country up to 1370.Inthe Bulgarian folklore is mentioned that the son of the Emperor perished with the death of the brave.
Knowledge 1: Maria-Irene Palaiologina
Irene Palaiologina (Irina; Ειρήνη Παλαιολογίνα) (1327 - after 1356) was a Byzantine princess and Bulgarian empress consort.She was also known as Maria Palaiologina (Μαρία Παλαιολογίνα).Her parents were Andronikos III Palaiologos and Anna of Savoy, whilst her siblings were John V Palaiologos and Michael Palaiologos.She married in 1336 Tsar Michael Asen IV of Bulgaria.Nothing else is known about her, except that she was an Orthodox Christian. [SEP] Knowledge 2: 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.
Knowledge 1: Michael Asen IV of Bulgaria
Michail Asen  (c. 1322–1355) was the eldest son of Ivan Alexander of Bulgaria from his marriage with Theodora of Wallachia.After his father acceded to the throne in 1331, the young prince was proclaimed co-Emperor.He was to succeed his father under the name Michael IV Asen.The heir to the throne was the pride of the royal family and was said to possess "all virtues".He married Maria, renamed Irina, the daughter of Andronikos III Palaiologos.In 1354–1355 the Ottoman Turks invaded Bulgaria and headed towards Plovdiv and Sofia.It is mentioned in an anonymous Bulgarian chronicle that Michail Asen gathered the Bulgarians and engaged the Turks near Sofia.The Bulgarians were defeated and suffered heavy casualties including Michail himself.But the battle was not in vain: the Ottomans failed to capture the cities and did not attack the country up to 1370.Inthe Bulgarian folklore is mentioned that the son of the Emperor perished with the death of the brave. [SEP] Knowledge 2: 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.

Answer: Ivan Alexander of Bulgaria