Margaret, Marchioness of Namur
Margaret, Marchioness of Namur (c. 1194 – 17 July 1270) was ruling Marchioness of Namur in 1229-1237.
She was the daughter of Peter II of Courtenay and Yolanda of Flanders.
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.
Geoffrey I of Vianden
Geoffrey I of Vianden" 7th duke of Vianden 1273- 1310"( 1310) was a son to duke Filips I of Vianden and Mary of Brabant- Perwez.
He succeeded to his father in 1273 in Vianden.
Geoffrey married Aleidis of Oudenaarde( 1260- 1305) and Lutgardis van Ligny and fathered:
Otto II of Nassau
Otto II of Nassau( – 1351) was a German nobleman.
He was a Count of Nassau- Dillenburg in Siegen and Dillenburg, and was a son of Count Heinrich of Nassau and Adelheid of Heinsberg.
Otto married Adelheid of Vianden, daughter of Philip of Vianden and Adelheid of Arnsberg.
They had four children:
John Westley
Rev. John Westley( 1636 – 78) was an English nonconformist minister.
He was the grandfather of John Wesley( founder of Methodism).
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.
Yolanda of Vianden
Mother Yolanda (or Yolande, Iolanda) of Vianden, O.P., (1231–1283) was the youngest daughter of Count Henry I of Vianden and Margaret, Marchioness of Namur.
She joined the Dominican monastery in Marienthal, Luxembourg, against the wishes of her parents when she was very young.
She later became its devout prioress and is now a legend in the history of that nation.
Princess Yolanda of Savoy
Princess Yolanda of Savoy (1 June 1901 – 16 October 1986) was the eldest daughter of King Victor Emmanuel III of Italy.
Lyon Cohen
Lyon Cohen( 1868–1937) was a Polish- born Canadian businessman and a philanthropist.
He was the grandfather of singer/ poet Leonard Cohen.

Question: Who is the maternal grandfather of Yolanda Of Vianden?
Answer: Peter II of Courtenay