Alfonso I of Asturias
Alfonso I of Asturias, called the Catholic(" el Católico"),( c. 693 – 757) was the third King of Asturias, reigning from 739 to his death in 757.
His reign saw an extension of the Christian domain of Asturias, reconquering Galicia and León.
He succeeded his brother- in- law Favila, and was succeeded by his son, Fruela I. Alfonso's youngest son, Mauregatus, also became king, and his daughter Adosinda was consort to king Silo of Asturias.
The dynasty started by Alfonso was known in contemporary Al- Andalus as the" Astur- Leonese dynasty".
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.
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.
Romanos Argyros (10th century)
Romanos Argyros was a Byzantine aristocrat and son-in- law of Emperor Romanos I Lekapenos.
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
Favila of Asturias
Fafila, Favila, or Favilac (died 739) was the second King of Asturias from 737 until his death.
He was the only son and successor of Pelagius, the first Asturian monarch, and was named after his paternal grandfather, who was the youngest son of Chindasuinth.
In 737 he founded the Church of Santa Cruz, in his capital of Cangas de Onís, but aside from this, nothing else about his reign is known.
He was said to have been killed by a bear on a hunt.
The hunt was probably a political tool for fostering political ties within his court, a common medieval practice.
Nonetheless, later chroniclers of the "Cronica ad Sebastianum" criticised him as given over to excessive levity.
Favila was buried with his wife Froiluba in the Church of Santa Cruz de Cangas de Onís.
According to the foundation inscription of Santa Cruz, he left children, but they did not succeed him.
He was succeeded by his brother-in-law Alfonso, husband of his sister Ermesinda.
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
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.
Ermesinda
Ermesinda (c. 720 or c. 730 — ?)
alternatively Ormisenda, Ermisenda, Ermesinde, Ermessenda) was queen consort of the Kingdom of Asturias, wife of King Alfonso I of Asturias ("Alfonso the Catholic").
She was the daughter of King Pelagius of Asturias and his queen, Gaudiosa.

Question: Who is the sibling-in-law of Favila Of Asturias?
Answer: Alfonso I of Asturias