Peter II, Duke of Bourbon
Peter II, Duke of Bourbon (1 December 1438 – 10 October 1503 in Moulins), was the son of Charles I, Duke of Bourbon, and Agnes of Burgundy, and a member of the House of Bourbon.
He and his wife Anne of France ruled as regents during the minority of Charles VIII of France.
Mathilde of Bourbon
Mathilde of Bourbon( – 18 June 1228) was a French noblewoman who was the ruling Lady of Bourbon from 1171 until her death.
Isabella of France, Dauphine of Viennois
" For other persons named Isabella of France, see Isabella of France( disambiguation)" Isabella of France and Burgundy( 1310 – April 1348) was the daughter of Philip V of France and Joan II, Countess of Burgundy.
Beatrice of Bourbon, Queen of Bohemia
Beatrice of Bourbon( 1320 – 23 December 1383) was a French noblewoman.
A member of the House of Bourbon, she was by marriage Queen of Bohemia and Countess of Luxembourg.
She was the youngest daughter of Louis I, Duke of Bourbon, and Mary of Avesnes.
Isabella of Valois, Duchess of Bourbon
Isabella of Valois, Duchess of Bourbon or" Isabella of France"( 1313 – 26 July 1383), was a Petit Fille of France, and a daughter of Charles of Valois by his third wife Mahaut of Châtillon.
She was the wife of Peter I, Duke of Bourbon.
Blanche of Bourbon
Blanche of Bourbon( 1339 – 1361) was Queen of Castile as the wife of King Peter.
She was one of the daughters of Peter I, Duke of Bourbon and Isabella of Valois.
Agnes of Burgundy, Duchess of Bourbon
Agnes of Burgundy (1407 – 1 December 1476), duchess of Bourbon (Bourbonnais) and Auvergne, countess of Clermont, was the daughter of John the Fearless (1371–1419) and Margaret of Bavaria.
Her maternal grandparents were Albert I, Duke of Bavaria and Margaret of Brieg.
Her paternal grandparents were Philip the Bold and Margaret III, Countess of Flanders.
Bonne of Bourbon
Bonne of Bourbon( 1341 – 19 January 1402) was a daughter of Peter I, Duke of Bourbon, and Isabella of Valois, and hence a sister of Joanna of Bourbon.
She served as regent of Savoy during the absence of her spouse from 1366 to 1367, in 1383, and during the minority of her grandson Count Amadeus VIII in 1391.
Tahira Wasti
Tahira Wasti( 1944 – March 11, 2012) was a well- known Pakistani writer and television actress.
She is best known for portrayal of Isabella of Castile in the TV drama" Shaheen".
Isabella of Bourbon
Isabella of Bourbon, Countess of Charolais (1434 – 25 September 1465) was the second wife of Charles the Bold, Count of Charolais and future Duke of Burgundy.
She was a daughter of Charles I, Duke of Bourbon and Agnes of Burgundy, and the mother of Mary of Burgundy, heiress of Burgundy.

Question: Who is Isabella Of Bourbon's maternal grandfather?
Answer: John the Fearless