Cynethryth
Cynethryth(" Cyneðryð"; died after AD 798) was a Queen of Mercia, wife of King Offa of Mercia and mother of King Ecgfrith of Mercia.
Cynethryth is the only Anglo- Saxon Queen consort in whose name coinage was definitely issued.
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.
Æthelred of Mercia
Æthelred (died after 704) was King of Mercia from 675 until 704.
He was the son of Penda of Mercia and came to the throne in 675, when his brother, Wulfhere of Mercia, died.
Within a year of his accession he invaded Kent, where his armies destroyed the city of Rochester.
In 679 he defeated his brother-in-law, Ecgfrith of Northumbria, at the Battle of the Trent: the battle was a major setback for the Northumbrians, and effectively ended their military involvement in English affairs south of the Humber.
It also permanently returned the kingdom of Lindsey to Mercia's possession.
However, Æthelred was unable to re-establish his predecessors' domination of southern Britain.
He was known as a pious and devout Christian king, and he made many grants of land to the church.
It was during his reign that Theodore, the Archbishop of Canterbury, reorganized the church's diocesan structure, creating several new sees in Mercia and Northumbria.
Æthelred befriended Bishop Wilfrid of York
when Wilfrid was expelled from his see in Northumbria; Æthelred made Wilfrid Bishop of the Middle Angles during his exile and supported him at the synod of Austerfield in about 702, when Wilfrid argued his case for the return of the ecclesiastical lands he had been deprived of in Northumbria.
Æthelred's wife, Osthryth, was a daughter of King Oswiu, one of the dominant 7th-century Northumbrian kings.
Osthryth was murdered in unknown circumstances in 697, and in 704 Æthelred abdicated, leaving the throne to Wulfhere's son Coenred.
Æthelred became a monk at Bardney, a monastery which he had founded with his wife, and was buried there.
Ceolred, who was Æthelred's son (though apparently not by Osthryth), became king after Coenred; it is also possible that Æthelred had another son named Ceolwald who was briefly king before Ceolred.
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.
Osthryth
Osthryth (died 697), queen of the Mercians, was the wife of King Æthelred and daughter of King Oswiu of Northumbria and his second wife Eanflæd.
She probably married Æthelred before 679 and was murdered by the nobles of Mercia.
Osthryth was not the first of her family to become a Mercian queen.
Her sister Alhflæd had married Peada, King of South Mercia 654-656.
After the death of Peada, who was allegedly murdered with Alhflæd's connivance, and possibly Osthryth's as well, she retreated to Fladbury in Worcestershire, to judge both from the place-name, which means "stronghold of Flæde", and from its subsequent history: sometime in the 690s Æthelred granted Fladbury to Oftfor, Bishop of Worcester, to re-establish monastic life there; however, this grant was later contested by Æthelheard, son of Oshere, who maintained that Æthelred had no right to give Fladbury away, as it had been the property of Osthryth.
Æthelheard claimed it as her kinsman and heir.
Æthelred and Osthryth loved and favoured Bardney Abbey in Lincolnshire.
Osthryth placed there the bones of her uncle Oswald of Northumbria, who was venerated as a saint.
It is clear from this story that Osthryth played a part in promoting the cult of St Oswald.
Many years later she persuaded Oswald's widow Cyneburh to take the veil.
Osthryth had to contend with major conflicts of loyalty.
In 679 her brother Ecgfrith of Northumbria fought a battle against Æthelred, in which Ecgfrith's brother Ælfwine was killed.
Bede tells us that he was "a young man of about eighteen years of age and much beloved in both kingdoms, for King Æthelred had married his sister."
The murder of Osthryth in 697 by Mercian nobles is unexplained in the sources that mention it.
Ann Williams attributes it to the hostility between the Mercians and the Northumbrians, while D. P. Kirby suggests that it may have been revenge for her sister's alleged involvement in Peada's murder.
H. P. R. Finberg speculates that she and her kinsman Oshere were suspected of trying to detach the kingdom of the Hwicce from Mercian overlordship.
Osthryth was buried at Bardney Abbey.
Osthryth was probably the mother of Æthelred's son, Ceolred, king of Mercia from 709 to 716.
Ælfwynn
Ælfwynn was the ruler of Mercia for a few months in 918, following her mother's death on 12 June 918.
She was the daughter of Æthelred, ruler of English Mercia, and Æthelflæd( styled The Lady of Mercia).
The" Anglo- Saxon Chronicle" states that she was" deprived of all control in Mercia, and was led into Wessex three weeks before Christmas".
Her accession was the only example of rule passing from one woman to another in the early medieval period in the British Isles.
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).
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.
Oswald, king of the Hwicce
Oswald was a brother of Osric, King of Anglo- Saxon kingdom of Hwicce, a sub-kingdom of Mercia in England.
In a problematic charter, possibly from 679, Oswald and his brother Osric were described as thegns( they are actually referred to as nepotes- usually translated as nephews or grandsons, but here probably meaning step- sons) of Æthelred, King of Mercia.

Question: Who is Æthelred Of Mercia's father-in-law?
Answer: Oswiu of Northumbria