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.
Abd al-Muttalib
Abd al- Muttalib Shaybah ibn Hashim( c. 497 – 578) was the grandfather of Islamic prophet Muhammad.
Henry Bryant (naturalist)
Henry Bryant( May 12, 1820 – February 2, 1867) was an American physician and naturalist.
He was the grandfather of Henry Bryant Bigelow.
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.
Lyon Cohen
Lyon Cohen( 1868–1937) was a Polish- born Canadian businessman and a philanthropist.
He was the grandfather of singer/ poet Leonard Cohen.
Fujiwara no Nagara
, also known as Fujiwara no Nagayoshi, was a Japanese statesman, courtier and politician of the early Heian period.
He was the grandfather of Emperor Yōzei.
Idwal Foel
Idwal Foel
(Idwal the Bald; died c. 942) or Idwal ab Anarawd
(Idwal son of Anarawd) was a 10th-century King of Gwynedd in Wales.
A member of the House of Aberffraw, he inherited the throne from his father, Anarawd ap Rhodri.
William of Malmesbury credited him as "King of the Britons" in the manner of his father.
Ieuaf
Idwal ab Idwal (died 988), usually known as Ieuaf  to distinguish him from his father Idwal Foel, was joint king of Gwynedd in northern Wales from 950 to 969.
He possibly also ruled Powys for some time.
Ieuaf was a son of King Idwal the Bald.
Upon his father's death in battle against the Anglo-Saxons in 942, he and his brother Iago were driven from their kingdom by their uncle Hywel Dda of Deheubarth, who took the crown for himself.
On Hywel's death in 950, Ieuaf and Iago were able to drive out Hywel's sons, their cousins, at the Battle of Carno and reclaim the kingdom.
However, fighting continued, with the brothers raiding as far south as Dyfed in 952 and their cousins raiding as far north as the Conwy valley in 954.
The southern princes were finally defeated at the Battle of Llanrwst and chased back to Ceredigion.
Having won, the brothers then began to quarrel among themselves.
Iago took Ieuaf prisoner in 969, and Ieuaf played no further role in Gwynedd.
Iago ruled another decade before Ieuaf's son Hywel usurped him in 979; according to historian John Edward Lloyd, Ieuaf remained in captivity until his death in 988.
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 Ieuaf's paternal grandfather?