Charles Lennox, 4th Duke of Richmond
Charles Lennox, 4th Duke of Richmond, 4th Duke of Lennox, 4th Duke of Aubigny,( 9 December 176428 August 1819) was a Scottish peer, soldier, politician, and Governor General of British North America.
Gilbert Talbot, 3rd Baron Talbot
Gilbert Talbot, 3rd Baron Talbot( c. 1332–1387) was an English nobleman and soldier.
He was the grandfather of John Talbot, 1st Earl of Shrewsbury.
John Westley
Rev. John Westley( 1636 – 78) was an English nonconformist minister.
He was the grandfather of John Wesley( founder of Methodism).
John Seymour (died 1491)
John Seymour( c. 1450 – 26 October 1491) of Wulfhall, of Stalbridge, of Stinchcombe and of Huish, all in Wiltshire, England, was warden of Savernake Forest and a prominent member of the landed gentry in the counties of Wiltshire, Somerset and Dorset.
He was the grandfather of Jane Seymour( c. 1508 – 1537), the third wife of King Henry VIII, and was thus great- grandfather of King Edward VI.
John Seymour, 4th Duke of Somerset
John Seymour, 4th Duke of Somerset and 3rd Marquess of Hertford (before 164629 April 1675) was an English peer and MP.
He was the only surviving son of William Seymour, 2nd Duke of Somerset, and Lady Frances Devereux, and he entered Gray's Inn in 1666.
He succeeded his nephew as the 4th Duke of Somerset in 1671.
In 1656 he married Sarah, daughter and co-heiress of Sir Edward Alston and widow of George Grimston.
He was elected Member of Parliament for Marlborough in 1661.
He died in 1675, childless, and was buried in Salisbury Cathedral.
He was succeeded in the dukedom by his cousin, Francis Seymour.
The Marquessate of Hertford became extinct on his death.
Henry Beaufort, 2nd Earl of Somerset
Henry Beaufort, 2nd Earl of Somerset(" probably" 26 November 1401 – 25 November 1418) was the eldest son of John Beaufort, 1st Earl of Somerset, and the grandson of John of Gaunt, 1st Duke of Lancaster and Katherine Swynford.
Henry succeeded his father as Earl of Somerset on 16 March 1410.
During his minority, his mother, Margaret Beaufort, Countess of Somerset held his lands for him until he reached the age of 15.
When Henry was seventeen, he was placed under the command of Thomas Beaufort, Duke of Exeter, his uncle, at the Siege of Rouen during the Hundred Years'
War where he, as well as a number of other nobles, met his demise, although the exact reasons of his death are unknown.
He never married and was succeeded by his younger brother, John Beaufort, 1st Duke of Somerset.
Catherine Fillol
Catherine Fillol( or Filliol)( c. 1507- c. 1535) was the daughter and co-heiress of Sir William Fillol( 1453- 9 July 1527), of Woodlands, Horton, Dorset, and of Fillol's Hall, Essex.
She became the first wife of Sir Edward Seymour, who went on to become the first Duke of Somerset of a new creation, Lord Protector of England and the uncle of King Edward VI, after his sister Jane married King Henry VIII.
A 17th- century marginal note to copy of" Vincent's Baronage" at College of Heralds alleged that she had had an affair with her father- in- law, Sir John Seymour.
However, there is no contemporary evidence to support this.
Catherine Fillol may have gone to a local convent, as this seems to be implied by a remark in her father's will.
The will was challenged by Sir Edward Seymour in 1531, on the basis that his father- in- law was not of sound mind.
In 1535, Sir Edward Seymour married his second wife Anne Stanhope, indicating that Catherine Fillol had probably died no later than early 1535.
Catherine Fillol had two sons, John Seymour( buried 19 December 1552), who died unmarried and without issue, and Edward Seymour.
Edward Seymour had ten more children by his second wife, including his eventual heir Edward Seymour, 1st Earl of Hertford.
When he was later created Duke of Somerset, his children by his first marriage were still considered legitimate, but the patent of nobility provides that the dukedom is to descend first to his heirs by Anne, and only in the event of the failure of that line to his heirs by Catherine.
With the death of Algernon, the seventh duke of Somerset in 1750, the Seymour Baronets of Berry Pomeroy Castle inherited the title of Duke of Somerset.
Consequently, the present Duke of Somerset is descended from Catherine Filliol.
Georgiana Seymour, Duchess of Somerset
Jane Georgiana Seymour, Duchess of Somerset( née Sheridan; 5 November 1809 – 14 December 1884), was the wife of Edward, Duke of Somerset.
Thomas Howard, 2nd Duke of Norfolk
Thomas Howard, 2nd Duke of Norfolk( 144321 May 1524), styled Earl of Surrey from 1483 to 1485 and again from 1489 to 1514, was an English nobleman and politician.
He was the eldest son of John Howard, 1st Duke of Norfolk, by his first wife, Catharina de Moleyns.
The Duke was the grandfather of both Queen Anne Boleyn and Queen Catherine Howard and the great grandfather of Queen Elizabeth I.
He served four monarchs as a soldier and statesman.
Frances Seymour, Duchess of Somerset
Frances Seymour, Duchess of Somerset ("née" Devereux; 30 September 1599 – 24 April 1674), was an English noblewoman who lived during the reigns of Elizabeth I, James I, Charles I and Charles II.
Her father was Robert Devereux, 2nd Earl of Essex,
Elizabeth
I's favourite who was executed for treason in 1601.
She was the second wife of William Seymour, 2nd Duke of Somerset, and the mother of his seven children.

Question: Who is the maternal grandfather of John Seymour, 4Th Duke Of Somerset?