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.
Abd al-Muttalib
Abd al- Muttalib Shaybah ibn Hashim( c. 497 – 578) was the grandfather of Islamic prophet Muhammad.
Damian Harris
Damian David Harris (born 2 August 1958) is a British film director and screenwriter.
He is the son of the actor Richard Harris and socialite Elizabeth Rees-Williams.
John Westley
Rev. John Westley( 1636 – 78) was an English nonconformist minister.
He was the grandfather of John Wesley( founder of Methodism).
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.
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
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.
Elizabeth Rees-Williams
Joan Elizabeth Rees-Williams, The Honourable Mrs Aitken (born 1 May 1936) is a Welsh socialite.
She appeared on the British television series "Question Time" in 1979, and in the documentaries "Biography" (1987) and "50 Films to See Before You Die" (2006).
She was born in Cardiff, the daughter of Alice Alexandra Constance ("née" Wills) and the politician David Rees-Williams, 1st Baron Ogmore.
She has three children from her first marriage, and gained at least eight stepchildren from her later marriages.

Question: Who is the maternal grandfather of Damian Harris?