Thomas Bruce, 2nd Earl of Ailesbury
Thomas Bruce, 2nd Earl of Ailesbury( later styled Aylesbury) and 3rd Earl of Elgin( 1656 – 16 December 1741) was an English politician and memoirist.
He was the son of Robert Bruce, 2nd Earl of Elgin, and Lady Diana Grey.
His maternal grandparents were Henry Grey, 1st Earl of Stamford, and Lady Anne Cecil, daughter of William Cecil, 2nd Earl of Exeter.
His" Memoirs", which were not published until long after his death, are a valuable source for English history in the last quarter of the seventeenth century.
Eleanor Beaufort
Lady Eleanor Beaufort( 1431 – 16 August 1501) was the daughter of Edmund Beaufort, 2nd Duke of Somerset( 1406- 1455), KG, and was a sister of the 3rd and 4th Dukes of Somerset.
Charles Somerset, 1st Earl of Worcester
Charles Somerset, 1st Earl of Worcester,( c. 146015 March 1526) was an English nobleman and politician.
He was the legitimised bastard son of Henry Beaufort, 3rd Duke of Somerset by his mistress Joan Hill.
Henry Bryant (naturalist)
Henry Bryant( May 12, 1820 – February 2, 1867) was an American physician and naturalist.
He was the grandfather of Henry Bryant Bigelow.
Edmund Beaufort, 2nd Duke of Somerset
Edmund Beaufort, 2nd Duke of Somerset, KG( 22 May 1455), was an English nobleman and an important figure in the Wars of the Roses and in the Hundred Years' War.
He also succeeded in the title of 4th Earl of Somerset and was created 1st Earl of Dorset and 1st Marquess of Dorset( previously held by his father and later forfeited), and Count of Mortain.
He was known for his deadly rivalry with Richard of York, 3rd Duke of York.
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.
John Manners, 4th Earl of Rutland
John Manners, 4th Earl of Rutland( c. 1559 – 24 February 1588) was the son of Henry Manners, 2nd Earl of Rutland, and Lady Margaret Neville, daughter of Ralph Neville, 4th Earl of Westmorland.
Margaret Holland, Duchess of Clarence
Margaret Holland (1385 – 30 December 1439) was a medieval English noblewoman.
She was a daughter of Thomas Holland, 2nd Earl of Kent, who was the son of Joan
"the Fair Maid of Kent"
(granddaughter of Edward
I of England, wife of Edward
the Black Prince and mother of Richard II of England).
Margaret's mother was Alice FitzAlan, daughter of Richard FitzAlan, 10th Earl of Arundel and Eleanor of Lancaster.
Margaret married John Beaufort, 1st Earl of Somerset, son of John of Gaunt and his mistress Katherine Swynford.
They had six children:
In 1399, she was invested as a Lady Companion, Order of the Garter (L.G.).
After Beaufort died in 1410 (in the Tower of London), she married his nephew Thomas of Lancaster, Duke of Clarence (1387–1421), the son of King Henry IV.
They had no children.
She died on 30 December 1439 at St. Saviour's Abbey, Bermondsey, in London, England.
Margaret and both her husbands are buried together in a carved alabaster tomb in Canterbury Cathedral that shows her lying between the two of them.
Ralph Neville, 3rd Earl of Westmorland
Ralph Neville, 3rd Earl of Westmorland( c. 1456 – 6 February 1499) was an English peer.
He was the grandfather of Ralph Neville, 4th Earl of Westmorland.
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.

Question: Who is Henry Beaufort, 2Nd Earl Of Somerset's maternal grandfather?
Answer: Thomas Holland, 2nd Earl of Kent