Question: Who is the paternal grandfather of Charles Bruce, 5Th Earl Of Elgin?

Context paragraphs:
title: James Lindsay, 5th Earl of Balcarres
paragraph_text: James Lindsay, 5th Earl of Balcarres( 14 November 1691 – 20 February 1768) was a Scottish peer, the son of Colin Lindsay, 3rd Earl of Balcarres and Lady Margaret Campbell, daughter of the Earl of Loudoun. He became the 5th Earl of Balcarres on 25 July 1736 on the death of his brother Alexander Lindsay, 4th Earl of Balcarres.
title: Charles Andrew Bruce
paragraph_text: Charles Andrew Bruce( 1768–1810) was briefly Governor of Prince of Wales Island( now called Penang) from March 24, 1810, until his death in office in December 1810. Bruce was one of the sons of Charles Bruce, 5th Earl of Elgin and Martha Bruce, Countess of Elgin and Kincardine( 1739 – 1810) and a brother of the collector Thomas Bruce, 7th Earl of Elgin, known for bringing the Elgin Marbles from Athens. The" Prince of Wales Island Gazette Extra" of 21 March 1810 recorded the appointment and arrival of Charles Andrew Bruce as Governor and the appointment of Colonel Norman Macalister and William Edward Phillips as members of Council.
title: Thomas Bruce, 2nd Earl of Ailesbury
paragraph_text: 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.
title: Ralph Neville, 3rd Earl of Westmorland
paragraph_text: 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.
title: Martha Bruce, Countess of Elgin and Kincardine
paragraph_text: Martha Bruce, Countess of Elgin and Kincardine( 1739 – 21 June 1810), born Martha White and known for most of her life as Lady Elgin, was the wife of Charles Bruce, 5th Earl of Elgin and 9th Earl of Kincardine, mother of the collector Thomas Bruce, 7th Earl of Elgin, and governess to Princess Charlotte of Wales, daughter of the future King George IV, at the time second in line to the throne.
title: John Boyle, 5th Earl of Cork
paragraph_text: John Boyle, 5th Earl of Cork and 5th Earl of Orrery, FRS (13 January 1707 – 16 November 1762) was a writer and a friend of Jonathan Swift, Alexander Pope and Samuel Johnson. The only son of Charles Boyle, 4th Earl of Orrery, and his wife Lady Elizabeth Cecil (1687–1708), daughter of John Cecil, 5th Earl of Exeter. He was born at Westminster and attended Christ Church, Oxford. He published a translation of the letters of Pliny the Younger in 1751, and "Remarks on the Life and Writings of Jonathan Swift" in the same year, and the "Memoirs of Robert Carey, 1st Earl of Monmouth". His "Letters from Italy" was published in 1774 by J. Duncombe.
title: Charles Bruce, 5th Earl of Elgin
paragraph_text: Charles Bruce, 5th Earl of Elgin and 9th Earl of Kincardine (6 July 1732 – 14 May 1771) was the son of William Bruce, 8th Earl of Kincardine. His mother was Janet Roberton, daughter of James Roberton (principal Lord of Session) and great-granddaughter of advocate and judge Lord Bedlay On 1 June 1759, he married Martha Whyte (1739-1810, who later became governess to Princess Charlotte of Wales. They had eight children: Elgin was Grand Master of Scottish Freemasons from 1761 to 1763 and a founding member of the Royal and Ancient Golf Club of St Andrews. He built the planned industrial village of Charlestown, Fife. He is buried in the southern transept of Dunfermline Abbey close to the grave of Robert the Bruce.
title: William Bruce, 8th Earl of Kincardine
paragraph_text: William Bruce, 8th Earl of Kincardine (died 8 September 1740), the son of Thomas Bruce, 7th Earl of Kincardine and Rachel Paunceforth, became the 8th Lord of Torry and the 8th Earl of Kincardine in 1740. His wife was Janet Roberton, the daughter of James Roberton, a Lord of Session (in turn a grandson of James Roberton, Lord Bedlay an ordinary Lord of Session during the Restoration.) and his wife Euphemia Burnett. The couple were second cousins, both descendants of Robert Bruce, Lord Broomhill. Bruce’s descent was through his father Thomas Bruce 7th Earl of Kincardine and his grandfather Alexander 4th Earl of Kincardine. His wife’s mother was the daughter of Janet Bruce, Alexander’s sister. Bruce had five children:
His son Charles Bruce inherited the Earldom of Elgin from the extinct line of Charles Bruce, the 3rd Earl of Ailesbury and 4th Earl of Elgin by virtue of their descent from Sir George Bruce, younger brother of Edward, the 1st Lord of Kinloss
title: Robert Bruce, 1st Earl of Ailesbury
paragraph_text: Robert Bruce, 1st Earl of Ailesbury( later styled Aylesbury) and 2nd Earl of Elgin, PC, FRS( ca. March 1626 – 20 October 1685), was a British politician who sat in the House of Commons from 1660 to 1663, when he inherited his father's title as Earl of Elgin.
title: James Bruce (1769–1798)
paragraph_text: James Bruce( 1769 –1798) was a Member of Parliament for Marlborough in the Parliament of Great Britain from 1796 until 1797. The youngest of the five sons of Charles Bruce, 5th Earl of Elgin, and of Martha Bruce, Countess of Elgin and Kincardine( 1739 – 1810), Bruce was a brother of the collector Thomas Bruce, 7th Earl of Elgin, known for bringing the Elgin Marbles from Athens. He entered Westminster School in 1778 and was at Christ Church, Oxford, from 1786 to 1790, when he became a member of Lincoln's Inn. For a year he was a Member of Parliament for Marlborough, taking a seat previously held by his uncle General Thomas Bruce, before resigning by" taking the Chiltern Hundreds". He left parliament to accept a post as a" précis" writer at the Foreign Office at a salary of £ 300 a year. On 10 July 1798, aged only twenty- nine, he was drowned while crossing the River Don at Barnby Dun in Yorkshire, when his horse was swept away by the stream. He was remembered as amiable and virtuous.

Reasoning steps:
Charles Bruce, 5th Earl of Elgin father William Bruce, 8th Earl of Kincardine
William Bruce, 8th Earl of Kincardine father Thomas Bruce, 7th Earl of Kincardine

Answer: spans: Thomas Bruce, 7th Earl of Kincardine