Charles Lennox, 3rd Duke of Richmond
Field Marshal Charles Lennox, 3rd Duke of Richmond, 3rd Duke of Lennox, 3rd Duke of Aubigny,( 22 February 1735 – 29 December 1806), styled Earl of March until 1750, was a British Army officer and politician.
He associated with the Rockingham Whigs and rose to hold the post of Southern Secretary for a brief period.
He was noteworthy for his support for the colonists during the American Revolutionary War, his support for a policy of concession in Ireland and his advanced views on the issue of parliamentary reform.
He went on to be a reforming Master- General of the Ordnance first in the Rockingham ministry and then in the ministry of William Pitt.
William Seymour, 2nd Duke of Somerset
William Seymour, 2nd Duke of Somerset,( 158824 October 1660) was an English nobleman and Royalist commander in the English Civil War.
Henry Beaufort, 3rd Duke of Somerset
Henry Beaufort, 3rd Duke of Somerset( 26 January 143615 May 1464) was an important Lancastrian military commander during the English Wars of the Roses.
He is sometimes numbered the 2nd Duke of Somerset, because the title was re-created for his father after his uncle died.
He also held the subsidiary titles of 5th Earl of Somerset, 2nd Marquess of Dorset and 2nd Earl of Dorset.
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.
Richard of Conisburgh, 3rd Earl of Cambridge
Richard of Conisburgh, 3rd Earl of Cambridge( c. July 1385 – 5 August 1415) was the second son of Edmund of Langley, 1st Duke of York, and Isabella of Castile.
He was beheaded for his part in the Southampton Plot, a conspiracy against King Henry V.
He was the father of Richard Plantagenet, 3rd Duke of York, and the grandfather of King Edward IV and King Richard III.
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.
John Mackay (poet)
John Mackay( 1656–1754), known as( The Blind Piper), was a Scottish Gaelic poet and composer, and the grandfather of William Ross.
Henry Seymour, Lord Beauchamp
Henry Seymour, Lord Beauchamp (
c. 1626 – 14 March 1654) was an English nobleman, third son of William Seymour, 2nd Duke of Somerset.
He had two elder brothers, but they both died unmarried in their twenties, so that in 1646, when he was about twenty, Henry became heir to his father and took his courtesy title of Lord Beauchamp.
On 28 June 1648, he married Mary Capell at Hadham Parva in Hertfordshire; they had one son and one daughter.
Like his father, he was a Cavalier, for which he was imprisoned in the Tower of London during the Commonwealth, 9 April to 9 September 1651, being released on £10,000 bond.
He died 14 March 1654 and was buried at Bedwyn Magna 30 March, having died at "Tilsy" according to the burial record in the parish register.
His widow married in 1657 Lord Herbert, later created the 1st Duke of Beaufort.
His children:
William Seymour, 3rd Duke of Somerset
William Seymour, 3rd Duke of Somerset (17 April 165212 December 1671) was the son of Henry Seymour, Lord Beauchamp, and Mary Capell.
As both his father and two elder uncles had predeceased him, he succeeded to the dukedom on the death of his grandfather William Seymour.
He died in 1671, unmarried and childless and was succeeded by his paternal uncle John Seymour.
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.

Question: Who is William Seymour, 3Rd Duke Of Somerset's paternal grandfather?
Answer: William Seymour, 2nd Duke of Somerset