Question: Who was the mother of the man who was King of England from 1483 to 1485?

Context paragraphs:
Thomas Arundell (1454–1485): Sir Thomas Arundell (1454–1485) was an English nobleman.  He was made a Knight of the Bath at the Coronation of Richard III in 1483.  Two years later, when Richard III was defeated at the Battle of Bosworth (1485), he was attainted for rebelling against the King.  Arundell then gave his support to Henry Tudor in his claim to the throne.  His marriage to the heiress, Katherine Dynham, brought great wealth to the Arundell family.  She was one of the four sisters and coheirs of John Dynham, 1st Baron Dynham.

Richard III of England: Richard III (2 October 1452 – 22 August 1485) was King of England from 1483 until his death in 1485, at the age of 32, in the Battle of Bosworth Field.  He was the last king of the House of York and the last of the Plantagenet dynasty.  His defeat at Bosworth Field, the last decisive battle of the Wars of the Roses, marked the end of the Middle Ages in England.  He is the subject of the historical play "Richard III" by William Shakespeare.

Ricardian (Richard III): Ricardians are people interested in altering the posthumous reputation of Richard III, King of England (reigned 1483–1485).  Richard III has long been portrayed unfavourably, most notably in William Shakespeare's play "Richard III", in which Richard is portrayed as having murdered his nephew, the crown prince of England, a 12 year old child at the time, in order to secure the English throne for himself.  Ricardians have worked in an effort to turn this around and to paint this portrayal, and the many other related assertions that followed, as most probably false politically motivated accusations.

John Twynyho: John Twynyho (c.1440 - 30 September 1485) ("alias" Twynyhoe, Twynihoe, etc.) of Cirencester, Bristol and Lechlade, all in Gloucestershire, was a lawyer and wealthy wool merchant who served as Recorder of Bristol, as a Member of Parliament for Bristol in Gloucestershire in 1472-5 and in 1484 and for the prestigious county seat Gloucestershire in 1476.  In 1478 he was Attorney General to Lord Edward (the future King Edward V (1483-1483)), eldest son and heir of King Edward IV.

Raby Castle: Raby Castle (grid reference [ NZ12912177] ) is near Staindrop in County Durham, England, among 200 acre of deer park.  It was built by John Neville, 3rd Baron Neville de Raby, between approximately 1367 and 1390.  Cecily Neville, the mother of the Kings Edward IV and Richard III, was born here.  After Charles Neville, 6th Earl of Westmorland, led the failed Rising of the North in favour of Mary, Queen of Scots in 1569 Raby Castle was taken into royal custody.

Edward IV of England: Edward IV (28 April 1442 – 9 April 1483) was the King of England from 4 March 1461 to 3 October 1470, and again from 11 April 1471 until his death in 1483.  He was the first Yorkist King of England.  The first half of his rule was marred by the violence associated with the Wars of the Roses, but he overcame the Lancastrian challenge to the throne at Tewkesbury in 1471 to reign in peace until his sudden death.  Before becoming king, he was 4th Duke of York, 7th Earl of March, 5th Earl of Cambridge and 9th Earl of Ulster.  He was also the 65th Knight of the Order of the Golden Fleece.

Hugh Conway (Lord Treasurer): Sir Hugh Conway was created Lord Treasurer of Ireland in 1494 by King Henry VII of England.  He replaced Sir James Ormonde as Lord Treasurer of Ireland.  In 1504 he was appointed Treasurer of Calais by Henry VII ( Cal.  Pat.  Rolls Henry VIII, vol.  ii, 365).  Hugh Conway was an early supporter of Henry Tudor, Earl of Richmond (later Henry VII), was sent by Margaret Beaufort, Henry's mother to Henry, in exile in France, in 1483 with a large sum of money and encouragement to invade England through Wales and seize the crown from Richard III.  Henry did so in 1485 and Richard was killed at the Battle of Bosworth, where Hugh was present.  Hugh was appointed Keeper of the Great Wardrobe by King Henry VII on 21 September 1485, was knighted in January 1486 at the coronation of Queen Elizabeth of York, daughter of King Edward IV, and married Elizabeth Courtenay, daughter of Sir Thomas Courtenay, Earl of Devon, in 1490.  Sir Hugh Conway was appointed Sheriff of Buckinghamshire and Bedfordshire by Henry VII in 1500.  Sir Hugh was a son of John ‘ Aer Conwy Hen ’ of Bodrhyddan Hall and Constable of Rhuddlan Castle, Flintshire, Wales, by his first marriage, and descended from the ancient line of Conway (Conwy = Wales) and de Crevecouer (The Journal Of The Flintshire Historical Society (Appendix D: Conwy Pedigree (British Museum Harleian MS 1971))).  Sir Hugh's younger half-brother was Edward Conway who married the heiress of Arrow and Alcester, Warwickshire, and was great-grandfather to Edward Conway, 1st Viscount Conway of Ragley Hall, ancestor of the present family of Seymour Conways, Marquis of Hertford.

Charles VIII of France: Charles VIII, called the Affable, French: "l'Affable" (30 June 1470 – 7 April 1498), was a monarch of the House of Valois who ruled as King of France from 1483 to his death in 1498.  He succeeded his father Louis XI at the age of 13.  His elder sister Anne of France acted as regent jointly with her husband Peter II, Duke of Bourbon until 1491 when the young king turned 21 years of age.  During Anne's regency, the great lords rebelled against royal centralisation efforts in a conflict known as the Mad War (1485-1488), which resulted in a victory for the royal government.

Richard III (disambiguation): Richard III (1452–1485) King of England from 26 June 1483 until his death on 22 August 1485.

White boar: The White Boar was the personal device or badge of the English King Richard III of England (1452—1485, reigned from 1483), and is an early instance of the use of boars in heraldry.

Supporting paragraphs: Raby Castle Richard III of England
Answer: Cecily Neville