Alexander Stewart, Earl of Buchan
Alexander Stewart, Earl of Buchan, Alasdair Mór mac an Rígh, and called the Wolf of Badenoch (1343 – 20 June 1405), was the third surviving son of King Robert II of Scotland and youngest by his first wife, Elizabeth Mure of Rowallan.
He was the first Earl of Buchan since John Comyn, from 1382 until his death.
Alexander married the widowed Euphemia I, Countess of Ross, but they had no children.
He did have a large family by his longtime mistress, Mairead inghean Eachainn.
Alexander was Justiciar of Scotia for a time, but not an effective one.
He held large territories in the north of Scotland before eventually losing a large part of them.
Alexander is remembered for his destruction of the royal burgh of Elgin and its cathedral.
His nickname was earned due to his notorious cruelty and rapacity, but there is no proof that it was used during his lifetime.
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.
John Vernou Bouvier III
John Vernou" Black Jack" Bouvier III( May 19, 1891 – August 3, 1957) was an American Wall Street stockbroker and socialite.
He was the father of First Lady Jacqueline Kennedy Onassis and of socialite Lee Radziwill, and was the father- in- law of John F. Kennedy.
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.
Ogawa Mataji
Viscount was a general in the early Imperial Japanese Army.
He was also the father- in- law of Field Marshal Gen Sugiyama.
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).
Mairead inghean Eachainn
Mairead inghean Eachainn, also known as Mairead nic Eachainn, was a consort of Alexander Stewart, Earl of Buchan (a man also known as the "Wolf of Badenoch").
She was the daughter of a man named Eachann, and probably the mother of several children, including Alexander's like-named son, Alexander Stewart, Earl of Mar.
Harry Smith (athlete)
Harry James Smith( July 30, 1888 – November 20, 1962) was an American long- distance runner.
He was most notable for competing in the 1912 Olympics in Stockholm.
He was also the father of Hart wrestling family matriarch Helen Hart and the father- in- law of Stu Hart.
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.
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.

Question: Who is Mairead Inghean Eachainn's father-in-law?
Answer: Robert II of Scotland