Cadwallon ab Ieuaf
Cadwallon ap Ieuaf (died 986) was a King of Gwynedd.
Cadwallon was the son of Ieuaf ab Idwal and succeeded to the throne of Gwynedd on the death of his brother Hywel ab Ieuaf in 985.
He only reigned for a year, for in
986 Maredudd ab Owain of Deheubarth invaded Gwynedd, slew Cadwallon and annexed his kingdom.
John Westley
Rev. John Westley( 1636 – 78) was an English nonconformist minister.
He was the grandfather of John Wesley( founder of Methodism).
Zhao Shoushan
Zhao Shoushan( 12 November 1894 – 20 June 1965) was a KMT general and later Chinese Communist Party politician.
He is the grandfather of Zhao Leji.
Fred Le Deux
Frederick" Fred" Le Deux( born 4 December 1934) was an Australian rules footballer who played with Geelong in the Victorian Football League( VFL).
He is the grandfather of Tom Hawkins.
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.
Henry Krause
Henry J." Red" Krause, Jr.( August 28, 1913 – February 20, 1987) was an American football offensive lineman in the National Football League for the Brooklyn Dodgers and the Washington Redskins.
He played college football at St. Louis University.
He is the grandfather of Jennifer Krause
He is the great grandfather of Payton Hoeing
Abd al-Muttalib
Abd al- Muttalib Shaybah ibn Hashim( c. 497 – 578) was the grandfather of Islamic prophet Muhammad.
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.
Lyon Cohen
Lyon Cohen( 1868–1937) was a Polish- born Canadian businessman and a philanthropist.
He was the grandfather of singer/ poet Leonard Cohen.
John Mackay (poet)
John Mackay( 1656–1754), known as( The Blind Piper), was a Scottish Gaelic poet and composer, and the grandfather of William Ross.

Question: Who is the paternal grandfather of Cadwallon Ab Ieuaf?
Answer: Idwal Foel