Stanley Blystone
William Stanley Blystone( August 1, 1894 – July 16, 1956) was an American film actor who made more than 500 films appearances between 1924 and 1956.
He was sometimes billed as William Blystone or William Stanley.
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.
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
Thomas Stanley, 1st Earl of Derby
Thomas Stanley, 1st Earl of Derby, (1435 – 29 July 1504) was an English nobleman and politician.
He was a titular King of Mann, and stepfather to King Henry VII of England.
He was the eldest son of Thomas Stanley, 1st Baron Stanley and Joan Goushill.
A landed magnate of immense power, particularly across the northwest of England where his authority went almost unchallenged, even by the Crown
, Stanley managed to remain in favour with successive kings throughout the Wars of the Roses until his death in 1504.
His estates included what is now Tatton Park in Cheshire, Lathom House in Lancashire, and Derby House in the City of London,
now the site of the College of Arms.
Although the king for the early part of his career, Henry VI, was head of the House of Lancaster, Stanley's marriage to Eleanor, daughter of Richard Neville, 5th Earl of Salisbury (a descendant of Edward III) and sister of Richard Neville, Earl of Warwick (‘Warwick the Kingmaker’)
in the late 1450s constituted a powerful alliance with the House of York.
This did him no harm, however, even after Warwick was toppled from power, and in 1472, with the House of York again occupying the English throne, he married his second wife Lady Margaret Beaufort, whose son, Henry Tudor, was the leading Lancastrian claimant.
He was the last to use the style ‘King of Mann’, his successors opting for the safer ‘Lord of Mann’.
Stanley was “a man of considerable acumen, and probably the most successful power-broker of his age”.
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.
Stan Ripley
William Stanley Ripley was an English football half back who played in the Southern League for Stoke.
John Hall (physician)
John Hall (1575 – 25 November 1635) was a physician and son-in-law of William Shakespeare.
William Stanley (Battle of Bosworth)
Sir William Stanley (c. 1435 – 16 February 1495) was an English soldier and the younger brother of Thomas Stanley, 1st Earl of Derby.
Stanley fought with his troops in several battles of the Wars of the Roses.
Stan Fox (footballer)
William Stanley Fox( 4 July 1906 – 20 August 1979) was an English footballer.

Question: Who is William Stanley (Battle Of Bosworth)'s sibling-in-law?
Answer: Lady Margaret Beaufort