Abd al-Muttalib
Abd al- Muttalib Shaybah ibn Hashim( c. 497 – 578) was the grandfather of Islamic prophet Muhammad.
Lyon Cohen
Lyon Cohen( 1868–1937) was a Polish- born Canadian businessman and a philanthropist.
He was the grandfather of singer/ poet Leonard Cohen.
Robert Gordon (diplomat)
Sir Robert Gordon (1791 – 8 October 1847) was a British diplomat.
Gordon was a younger son of George Gordon, Lord Haddo (himself the eldest son of the 3rd Earl of Aberdeen) and a brother of the 4th Earl of Aberdeen.
He was educated at St John's College, Cambridge.
From 1826 to 1828, he was Envoy Extraordinary to Brazil, to the Ottoman Empire from 1828 to 1831 and to Austria from 1841 to 1847.
He took leave twice during his stay in Vienna, with John Fiennes-Twisleton-Crampton (September to October 1842) and Arthur Magenis (31 July 1845 to April 1846) taking charge in his place.
In 1830, he acquired a long-term lease of Balmoral Castle.
He died in 1847 as the result of choking on a fish bone.
Prince Albert bought the estate from his trustees a year later as a gift for his wife, Queen Victoria.
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.
Robert Gordon (actor)
Robert Gordon( March 3, 1895 – October 26, 1971), born Robert Gordon Duncan, was an American silent film actor.
He was born in Belleville, Kansas and died at the age of 76 in Victorville, California.
He is credited with appearances in 35 films from 1917 to 1949.
John Westley
Rev. John Westley( 1636 – 78) was an English nonconformist minister.
He was the grandfather of John Wesley( founder of Methodism).
Guillaume Wittouck
Guillaume Wittouck( 1749- 1829) was a Belgian lawyer and High Magistrate.
He was the Grandfather of industrialist Paul Wittouck.
George Gordon, Lord Haddo
George Gordon, Lord Haddo (28 January 1764 – 2 October 1791) was a Scottish Freemason and the eldest son of George Gordon, 3rd Earl of Aberdeen.
On 18 June 1782, Haddo married Charlotte Baird, a sister of Sir David Baird, Bt.
and they had seven children:
Haddo was Grand Master of the Grand Lodge of Scotland from 1784 to 1786.
He predeceased his father in 1791 and on the latter's death in 1801
, the earldom passed to Haddo's eldest son, George.
Sir Robert Gilmour, 1st Baronet
Brigadier- General Sir Robert Gordon Gilmour, 1st Baronet,( 27 February 1857 – 24 June 1939), born Robert Gordon Wolrige Gordon( he changed his name in 1887), was a British army officer and Captain of the Royal Company of Archers.

Question: Who is Robert Gordon (Diplomat)'s paternal grandfather?
Answer: George Gordon, 3rd Earl of Aberdeen