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.
Abd al-Muttalib
Abd al- Muttalib Shaybah ibn Hashim( c. 497 – 578) was the grandfather of Islamic prophet Muhammad.
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.
Lyon Cohen
Lyon Cohen( 1868–1937) was a Polish- born Canadian businessman and a philanthropist.
He was the grandfather of singer/ poet Leonard Cohen.
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
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.
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.
Ottaviano Riario
Ottaviano Riario (September 1479 – 1523) was an Italian condottiero and Lord of Imola and Forlì.
Despite his nominal leadership, the real power lay with his mother Caterina Sforza.
Caterina Sforza
Caterina Sforza (1463 – 28 May 1509) was an Italian noblewoman along with the Countess of Forlì and Lady of Imola, firstly with her husband Girolamo Riario, and after his death as a regent of her son Ottaviano.
Caterina was the illegitimate daughter of Galeazzo Maria Sforza, Duke of Milan and Lucrezia, the wife of the courtier Gian Piero Landriani, a close friend of the Duke.
She was raised in the refined Milanese court.
The descendant of a dynasty of noted condottieri, from an early age, Caterina distinguished herself through her bold and impetuous actions taken to safeguard her possessions from possible usurpers and to defend her dominions from attack, when they were involved in political intrigues.
In her private life Caterina was devoted to various activities, including experiments in alchemy and a love of hunting and dancing.
She had many children, but
only the youngest, Captain Giovanni dalle Bande Nere, inherited his mother's forceful, militant personality.
Caterina's resistance to Cesare Borgia meant she had to face his fury and imprisonment.
Once she gained her freedom in Rome, she led a quiet life in Florence.
In the final years of her life, she confided to a monk: "Se io potessi scrivere tutto, farei stupire
il mondoIf
I could write everything that happened, I would shock the world").

Question: Who is Ottaviano Riario's maternal grandfather?
Answer: Galeazzo Maria Sforza