Question: Who is William Savile, 2Nd Marquess Of Halifax's maternal grandfather?

Knowledge 1: William Savile, 2nd Marquess of Halifax
William Savile, 2nd Marquess of Halifax (1665 – 31 August 1700) was the son of George Savile, 1st Viscount Halifax and Dorothy Savile, Viscountess Halifax (née Spencer).He was educated in Geneva in 1677 and matriculated at Christ Church, Oxford in 1681, but did not take a degree.He travelled on the continent in 1684–1687, returning on his brother's death.From that time, he was known as Lord Elland, from his father's subsidiary title of Baron Savile of Elland.He was a Member of Parliament for Newark-on-Trent from 1689 to 1695.He was a Tory and voted in 1689 that the throne was not vacant.He had four daughters including:He died in 1700, at an early age from "an inward feavour".Having died without male issue, the title became extinct, but was succeeded in his baronetcy by a cousin. [SEP] Knowledge 2: Dorothy Savile, Viscountess Halifax
Dorothy Savile, Viscountess Halifax (née Spencer; 1640 – 16 December 1670) was the first wife of George Savile, 1st Viscount Halifax, and the mother of the 2nd Marquess.Dorothy was the daughter of Henry Spencer, 1st Earl of Sunderland, and his wife, the former Lady Dorothy Sidney (or Sydney).Lady Dorothy married George Savile on 29 December 1656, at St Giles in the Fields in London.They had two children:In 1667, George Savile was created Viscount Halifax.Following his wife's death, he remarried, in 1672, his second wife being Gertrude Pierrepont, daughter of William Pierrepont of Thoresby.His elevation to the title of Marquess of Halifax came in 1682, some years after Dorothy's death.
Knowledge 1: Dorothy Savile, Viscountess Halifax
Dorothy Savile, Viscountess Halifax (née Spencer; 1640 – 16 December 1670) was the first wife of George Savile, 1st Viscount Halifax, and the mother of the 2nd Marquess.Dorothy was the daughter of Henry Spencer, 1st Earl of Sunderland, and his wife, the former Lady Dorothy Sidney (or Sydney).Lady Dorothy married George Savile on 29 December 1656, at St Giles in the Fields in London.They had two children:In 1667, George Savile was created Viscount Halifax.Following his wife's death, he remarried, in 1672, his second wife being Gertrude Pierrepont, daughter of William Pierrepont of Thoresby.His elevation to the title of Marquess of Halifax came in 1682, some years after Dorothy's death. [SEP] Knowledge 2: Sir Samuel Grimston, 3rd Baronet
Sir Samuel Grimston, 3rd Baronet (7 January 1643 – October 1700) of Gorhambury House, Hertfordshire was an English politician.Grimston was the second and only one of the six sons of Sir Harbottle Grimston, 2nd Baronet who survived him.He was born 7 January 1643.His mother was Sir Harbottle's first wife, Mary, daughter of Sir George Croke.He was elected Member of Parliament for St Albans at a by-election in May 1668.He was not returned to the parliament of 1678, but was re-elected in 1679 and 1680.During the reign of James II he remained in private life, being, it is said, much disliked by the king, who expressly excepted him from pardon in the manifesto he issued when he contemplated landing in England (1692).Grimston succeeded to his father's baronetcy and estates, including Gorhambury, in 1683, and was returned a member of the Convention Parliament of 22 January 1689.From that time till May 1699 he sat continuously for his old borough of St Albans.He married first Elizabeth, the eldest daughter of Heneage Finch, 1st Earl of Nottingham, by whom he was father of a daughter, Elizabeth (d. 1694), who became first wife of William Savile, 2nd Marquess of Halifax.Grimston's second wife was Lady Anne, sixth daughter of John Tufton, 2nd Earl of Thanet.By her he had a son and daughter, but both died young, and on his death, which occurred in October 1700, the Grimston baronetcy became extinct.Grimston left the family estates, which he had increased by the purchase of the manor of Windridge from Henry Osbaston, to his great-nephew, William Luckyn Grimston, second son of Sir William Luckyn of Messing Hall.
Knowledge 1: William Savile, 2nd Marquess of Halifax
William Savile, 2nd Marquess of Halifax (1665 – 31 August 1700) was the son of George Savile, 1st Viscount Halifax and Dorothy Savile, Viscountess Halifax (née Spencer).He was educated in Geneva in 1677 and matriculated at Christ Church, Oxford in 1681, but did not take a degree.He travelled on the continent in 1684–1687, returning on his brother's death.From that time, he was known as Lord Elland, from his father's subsidiary title of Baron Savile of Elland.He was a Member of Parliament for Newark-on-Trent from 1689 to 1695.He was a Tory and voted in 1689 that the throne was not vacant.He had four daughters including:He died in 1700, at an early age from "an inward feavour".Having died without male issue, the title became extinct, but was succeeded in his baronetcy by a cousin. [SEP] Knowledge 2: Sir Samuel Grimston, 3rd Baronet
Sir Samuel Grimston, 3rd Baronet (7 January 1643 – October 1700) of Gorhambury House, Hertfordshire was an English politician.Grimston was the second and only one of the six sons of Sir Harbottle Grimston, 2nd Baronet who survived him.He was born 7 January 1643.His mother was Sir Harbottle's first wife, Mary, daughter of Sir George Croke.He was elected Member of Parliament for St Albans at a by-election in May 1668.He was not returned to the parliament of 1678, but was re-elected in 1679 and 1680.During the reign of James II he remained in private life, being, it is said, much disliked by the king, who expressly excepted him from pardon in the manifesto he issued when he contemplated landing in England (1692).Grimston succeeded to his father's baronetcy and estates, including Gorhambury, in 1683, and was returned a member of the Convention Parliament of 22 January 1689.From that time till May 1699 he sat continuously for his old borough of St Albans.He married first Elizabeth, the eldest daughter of Heneage Finch, 1st Earl of Nottingham, by whom he was father of a daughter, Elizabeth (d. 1694), who became first wife of William Savile, 2nd Marquess of Halifax.Grimston's second wife was Lady Anne, sixth daughter of John Tufton, 2nd Earl of Thanet.By her he had a son and daughter, but both died young, and on his death, which occurred in October 1700, the Grimston baronetcy became extinct.Grimston left the family estates, which he had increased by the purchase of the manor of Windridge from Henry Osbaston, to his great-nephew, William Luckyn Grimston, second son of Sir William Luckyn of Messing Hall.

Answer: Henry Spencer, 1st Earl of Sunderland