Question: Who is the paternal grandfather of Robert Bertie, 4Th Duke Of Ancaster And Kesteven?

Knowledge 1: Robert Bertie, 4th Duke of Ancaster and Kesteven
Robert Bertie, 4th Duke of Ancaster and Kesteven, PC (17 October 1756 – 8 July 1779), styled Lord Robert Bertie until 1758 and Marquess of Lindsey between 1758 and 1778, was a British peer.He was born in Grimsthorpe, the second son of the General Peregrine Bertie, 3rd Duke of Ancaster and Kesteven (died 1778) and Mary Panton (died 1793)On the death of his elder brother, Peregrine Thomas Bertie, Marquess of Lindsey, on 12 December 1758, he inherited the courtesy title of Marquess of Lindsey.He was educated at Eton College and St John's College, Cambridge.About 1777, he served as a volunteer in North America.A lieutenant in the 7th Regiment of Foot, on 20 January 1778, he was promoted to a captaincy in the 15th Regiment of Foot.On his father's death on 12 August 1778, he succeeded as 4th Duke of Ancaster and Kesteven, 4th Marquess of Lindsey, 7th Earl of Lindsey, 20th Baron Willoughby de Eresby and Hereditary Lord Great Chamberlain.He was the last to hold the Lord Great Chamberlainship as an undivided office.On 12 February 1779 he was invested as Privy Counsellor and was Lord Lieutenant of Lincolnshire.He never married and died in Grimsthorpe on 8 July 1779 from scarlet fever.He was buried on 22 July 1779 in Edenham.On his death, the Hereditary Lord Great Chamberlainship and the Barony Willoughby de Eresby fell into abeyance between his two sisters, all other titles of his passed to his uncle.An illegitimate daughter of the 4th duke, Susan, was married to Banastre Tarleton; but there were no children. [SEP] Knowledge 2: Peregrine Bertie, 3rd Duke of Ancaster and Kesteven
General Peregrine Bertie, 3rd Duke of Ancaster and Kesteven (171412 August 1778), styled Lord Willoughby de Eresby from 1715 to 1723 and Marquess of Lindsey from 1735 to 1742 was the son of Peregrine Bertie, 2nd Duke of Ancaster and Kesteven.He married, firstly, Elizabeth Blundell (died 1743), widow of Charles Gounter Nicoll on 22 May 1735.He married, secondly, Mary Panton, on 27 November 1750.They had six children:
On the death of his father in 1742, he succeeded him in the dukedom and as Lord Great Chamberlain and Lord Lieutenant of Lincolnshire, and was appointed to the Privy Council.He gained the rank of Major-General on 19 January 1755, Lieutenant-General on 3 February 1759 and General on 25 May 1772.
Knowledge 1: Peregrine Bertie, 3rd Duke of Ancaster and Kesteven
General Peregrine Bertie, 3rd Duke of Ancaster and Kesteven (171412 August 1778), styled Lord Willoughby de Eresby from 1715 to 1723 and Marquess of Lindsey from 1735 to 1742 was the son of Peregrine Bertie, 2nd Duke of Ancaster and Kesteven.He married, firstly, Elizabeth Blundell (died 1743), widow of Charles Gounter Nicoll on 22 May 1735.He married, secondly, Mary Panton, on 27 November 1750.They had six children:
On the death of his father in 1742, he succeeded him in the dukedom and as Lord Great Chamberlain and Lord Lieutenant of Lincolnshire, and was appointed to the Privy Council.He gained the rank of Major-General on 19 January 1755, Lieutenant-General on 3 February 1759 and General on 25 May 1772. [SEP] Knowledge 2: Lord Vere Bertie
Lord Vere Bertie (c.1712 – 13 September 1768) was a British politician, a younger son of the Duke of Ancaster and Kesteven who represented Boston, Lincolnshire in Parliament from 1741 to 1754.Bertie was the third son of Robert Bertie, 1st Duke of Ancaster and Kesteven, and the first son by his second marriage to Albinia Farrington.He was educated at Westminster School from 1724 to 1728, and was commissioned an ensign in the 2nd Regiment of Foot Guards in 1729, leaving the Army by 1740.Bertie married Anne Casey, the illegitimate daughter of Sir Cecil Wray, 11th Baronet, on 4 October 1736.They had two sons and two daughters.The sons died young; the two daughters, his heirs, were:In the 1741 election, Bertie was returned as Member of Parliament for Boston on his family's interest.He voted with the Carteret ministry to support the Hanoverian army in 1742, but defected from them on the same question in January 1744.He did not vote in the 1746 division on the Hanoverian subsidies, but after the 1747 election, when he was returned again after a contest, was considered to have gone into opposition to the Pelham ministry.Bertie stood down from Parliament in 1754 and died on 13 September 1768.
Knowledge 1: Robert Bertie, 4th Duke of Ancaster and Kesteven
Robert Bertie, 4th Duke of Ancaster and Kesteven, PC (17 October 1756 – 8 July 1779), styled Lord Robert Bertie until 1758 and Marquess of Lindsey between 1758 and 1778, was a British peer.He was born in Grimsthorpe, the second son of the General Peregrine Bertie, 3rd Duke of Ancaster and Kesteven (died 1778) and Mary Panton (died 1793)On the death of his elder brother, Peregrine Thomas Bertie, Marquess of Lindsey, on 12 December 1758, he inherited the courtesy title of Marquess of Lindsey.He was educated at Eton College and St John's College, Cambridge.About 1777, he served as a volunteer in North America.A lieutenant in the 7th Regiment of Foot, on 20 January 1778, he was promoted to a captaincy in the 15th Regiment of Foot.On his father's death on 12 August 1778, he succeeded as 4th Duke of Ancaster and Kesteven, 4th Marquess of Lindsey, 7th Earl of Lindsey, 20th Baron Willoughby de Eresby and Hereditary Lord Great Chamberlain.He was the last to hold the Lord Great Chamberlainship as an undivided office.On 12 February 1779 he was invested as Privy Counsellor and was Lord Lieutenant of Lincolnshire.He never married and died in Grimsthorpe on 8 July 1779 from scarlet fever.He was buried on 22 July 1779 in Edenham.On his death, the Hereditary Lord Great Chamberlainship and the Barony Willoughby de Eresby fell into abeyance between his two sisters, all other titles of his passed to his uncle.An illegitimate daughter of the 4th duke, Susan, was married to Banastre Tarleton; but there were no children. [SEP] Knowledge 2: Lord Vere Bertie
Lord Vere Bertie (c.1712 – 13 September 1768) was a British politician, a younger son of the Duke of Ancaster and Kesteven who represented Boston, Lincolnshire in Parliament from 1741 to 1754.Bertie was the third son of Robert Bertie, 1st Duke of Ancaster and Kesteven, and the first son by his second marriage to Albinia Farrington.He was educated at Westminster School from 1724 to 1728, and was commissioned an ensign in the 2nd Regiment of Foot Guards in 1729, leaving the Army by 1740.Bertie married Anne Casey, the illegitimate daughter of Sir Cecil Wray, 11th Baronet, on 4 October 1736.They had two sons and two daughters.The sons died young; the two daughters, his heirs, were:In the 1741 election, Bertie was returned as Member of Parliament for Boston on his family's interest.He voted with the Carteret ministry to support the Hanoverian army in 1742, but defected from them on the same question in January 1744.He did not vote in the 1746 division on the Hanoverian subsidies, but after the 1747 election, when he was returned again after a contest, was considered to have gone into opposition to the Pelham ministry.Bertie stood down from Parliament in 1754 and died on 13 September 1768.

Answer: Peregrine Bertie, 2nd Duke of Ancaster and Kesteven