John Westley
Rev. John Westley( 1636 – 78) was an English nonconformist minister.
He was the grandfather of John Wesley( founder of Methodism).
Lyon Cohen
Lyon Cohen( 1868–1937) was a Polish- born Canadian businessman and a philanthropist.
He was the grandfather of singer/ poet Leonard Cohen.
Abd al-Muttalib
Abd al- Muttalib Shaybah ibn Hashim( c. 497 – 578) was the grandfather of Islamic prophet Muhammad.
Archibald Hope, Lord Rankeillor
Sir Archibald Hope, Lord Rankeillor (1639 – 10 October 1706) was a Scottish advocate and judge, the second son of John Hope, Lord Craighall, the grandfather of the botanist John Hope and the great-grandfather of the chemist Thomas Charles Hope, FRSE.
Sir Archibald Campbell, 2nd Baronet
Sir Archibald Campbell of Succoth, Lord Succoth,
2nd Baronet (1 August 1769 – 23 July 1846) was a Scottish advocate and judge.
His country house was Garscube House, succeeding to the estate in 1823, upon his father's death.
He rebuilt the house at Garscube in 1827, to a design by William Burn.
He added Cumlodden, Blairwhoisk, Sommerson and Gartowhern to the family estate.
The son of Sir Ilay Campbell and Susan Mary Murray, he was admitted to the Faculty of Advocates in 1791, and in 1809 became a Senator of the College of Justice under the judicial title Lord Succoth.
A member of the Highland Society (1813), he was elected a Fellow of the Royal Society of Edinburgh on 4 June 1821, upon the proposal of Alexander Maconochie.
Gilbert Talbot, 3rd Baron Talbot
Gilbert Talbot, 3rd Baron Talbot( c. 1332–1387) was an English nobleman and soldier.
He was the grandfather of John Talbot, 1st Earl of Shrewsbury.
John Campbell (1798–1830)
John Campbell (28 May 1798 – 3 July 1830) was a Scottish advocate and politician.
He was the eldest surviving son of judge Sir Archibald Campbell, 2nd Baronet (Lord Succoth) of Succoth, Dunbarton, educated at Harrow School and became an advocate in 1821.
He predeceased his father, who died in 1846.
He was the Member of Parliament (MP) for Dunbartonshire from 1826–1830.
He married Anna Jane Sitwell, daughter of Francis Sitwell.
His eldest son Archibald Campbell (1825–66) succeeded John's father as 3rd Baronet and was Conservative MP for Argyllshire, 1851-57.
He was in turn succeeded by his younger brother George Campbell, 4th Baronet (1829–74).
John Christian Kunkel
John Christian Kunkel (September 18, 1816 – October 14, 1870) was a Whig and Republican member of the U.S. House of Representatives from Pennsylvania.
He was the grandfather of John Crain Kunkel.
Prithvipati Shah
Prithvipati Shah( ?–1716) was the king of the Gorkha Kingdom in the Indian subcontinent, present- day Nepal.
He was the grandfather of Nara Bhupal Shah.
Kaya Alp
Kaya Alp was, according to Ottoman tradition, the son of Kızıl Buğa and the father of Suleyman Shah, who was, in turn, the grandfather of Ertuğrul, and the great grandfather of the Ottoman Empire founder, Osman I.

Question: Who is John Campbell (1798–1830)'s paternal grandfather?
Answer: Ilay Campbell