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.
Diarmait Mac Giolla Chríost
Diarmait Mac Giolla Chriost is an Irish academic in the area of linguistics.
Ruaidrí Ua Conchobair
Ruaidrí Ua Conchobair (Modern Irish:
Ruaidhrí Ó Conchobhair, or, Ruairí Ó Conchúir; commonly anglicised as Rory O'Connor or Roderic O'Connor)
(– 2 December 1198) was King of Connacht from 1156 to 1186, and High King of Ireland from 1166 to 1193.
He was the last High King of Ireland before the Norman invasion (Brian Ua Néill and Edward Bruce both claimed the title with opposition in later years).
Ruaidrí was one of over twenty sons of King Tairrdelbach Ua Conchobair (1088–1156).
He and his sister Mór were Tairrdelbach's only children from his third wife, Cailech Dé Ní hEidin of Aidhne.
Diarmait mac Cerbaill (King of Osraige)
Diarmait mac Cerbaill was a king of Osraige from 894 to 905, and again from 908 to 928 AD.
He is not to be confused with the early Irish high king Diarmait mac Cerbaill.
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.
Diarmait Ó Conchobair
Diarmait mac Ruaidrí Ó Conchobair, Prince of Connacht, died 1221.
Diarmait was one of the younger sons of King of Ireland, Ruaidrí Ua Conchobair (died 1198).
The Annals of the Four Masters, "sub anno" 1203, say of him:
The Annals of Lough Ce give an account of Diarmait's death:
"Diarmaid, son of Ruaidhri, son of Toirdhelbhach Mór O'Conchobhair, was slain by Thomas Mac Uchtraigh as he was coming from Insi-Gall, whilst collecting a fleet for the purpose of acquiring the sovereignty of Connacht; and this was a great pity, viz.:—the materies of a king of Erinn to fall so before his time."
Insi Gall was either the Hebrides or the Isle of Man, both of which compromised the Kingdom of the Isles, ruled in 1221 by Rǫgnvaldr Guðrøðarson, King of the Isles (1187–1226).
Diarmait's recorded children were sons Diarmait (fl. 1237), Donnchad (fl. 1237), Muirchertach (k. 1237) and Cormac.
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.
Abd al-Muttalib
Abd al- Muttalib Shaybah ibn Hashim( c. 497 – 578) was the grandfather of Islamic prophet Muhammad.
Donnchad mac Gilla Pátraic
Donnchad mac Gilla Pátraic( Donagh MacGillapatrick)( died 1039), was King of Osraige and King of Leinster.
A daughter of Gilla Pátraic was Aífe, mother of Diarmait mac Máel na m Bó, King of Leinster( died 1072).

Question: Who is Diarmait Ó Conchobair's paternal grandfather?
Answer: Tairrdelbach Ua Conchobair