Eusebius (consul 359)
Flavius Eusebius( died after AD 371) was a Roman Senator, who was the brother- in- law of the emperor Constantius II.
Eudamidas I
Eudamidas I (Greek:
Εὐδαμίδας, reigned 331 BC – c. 305 BC)
was a Spartan king of the Eurypontid line, son of Archidamus III and brother of Agis III, whom he succeeded.
He married the wealthy Archidamia, and they had two children, Archidamus IV and Agesistrata.
There is evidence that Eudamidas I owned the half of his wife's wealth in land.
His reign of Sparta was a time of peace.
Pausanias devotes more space to Agis II (427–400 BC) and Agesilaus II (400–360 BC) than to other kings, such as Agis III (338–330 BC) and Eudamidas I, whose lives he passed by briefly, as the Eurypontid line ‘fades’.
Archidamia
Archidamia  (c. 340-241 BC) was a Spartan queen, wife of Eudamidas I, mother of Archidamus IV and Agesistrata, grandmother of Eudamidas II, great-grandmother and grandmother of Agis IV.
Greg Penner
Gregory B. Penner( born December 18, 1969) is an American businessman and venture capitalist.
Penner was named the chairman of Walmart on June 5, 2015.
He is the son-in- law of S. Robson Walton and the grandson- in- law of Sam Walton, the founder of Walmart.
Robert Vadra
Robert Vadra is an Indian businessman, entrepreneur and the husband of Priyanka Gandhi.
He is the son -in- law of Sonia Gandhi and Rajiv Gandhi, and the brother- in- law of Rahul Gandhi.
Wyndham Goold
Wyndham Goold( 1812-1854) was a Member of Parliament( MP) for County Limerick from 1850 to 1854.
Goold was educated at Westminster School and Trinity College, Dublin.
He was the son in law of Frederick Falkiner Goold, Archdeacon of Raphoe and brother in law of Bishop Hamilton Verschoyle
Nick Sidi
Nick Sidi( born 22 February 1966 in Manchester, England) is an English actor.
He is the son -in- law of actress Rosalind Knight and brother- in- law of actress Susannah Elliott- Knight.
He often plays drama or comedy roles on television and frequently appears in BBC dramas.
Robert W. Levering
Robert Woodrow Levering( October 3, 1914 – August 11, 1989) was a U.S. Representative from Ohio, son-in- law of Usher L. Burdick and brother- in- law of Quentin N. Burdick.
Charles Francis Norton
Charles Francis Norton( 1807 – 1835) was a 19th- century Member of Parliament for Guildford.
Norton was also a Captain of 52nd Light Infantry; son-in- law of Sir Colin Campbell; brother- in- law of writer Caroline Norton
Hypatius (consul 359)
Flavius Hypatius( c. 340- died after AD 383) was a Roman Senator, who was the brother- in- law of the Roman emperor Constantius II.

Question: Who is the sibling-in-law of Archidamia?
Answer: Agis III