Princess Isabella Antonie of Croÿ
Princess Isabella of Croÿ( Isabella Antonie Eleonore Natalie Klementine; 7 October 1890 – 30 March 1982) was a Princess of Croÿ by birth and a Princess of Bavaria and member of the House of Wittelsbach through her marriage to Prince Franz of Bavaria, a son of Ludwig III, the last King of Bavaria.
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.
Princess Isabella of Bavaria
Princess Isabella of Bavaria (
Marie Elisabeth Luise Amalie Elvire Blanche Eleonore; 31 August 1863 – 26 February 1924) was the third child and eldest daughter of Prince Adalbert of Bavaria and his wife Infanta Amalia of Spain.
By her marriage to Prince Thomas, Duke of Genoa, she became referred to as the Duchess of Genoa.
Prince Adalbert of Bavaria (1828–1875)
Prince Adalbert Wilhelm
Georg Ludwig of Bavaria (Munich, 19 July 1828 –
Nymphenburg Palace, 21 September 1875) was the ninth child and fourth son of Ludwig I of Bavaria and Therese of Saxe-Hildburghausen.
Princess Maria Adelaide of Savoy-Genoa
Princess Adelaide of Savoy- Genoa( Maria Adelaide Vittoria Amelia; 25 April 1904 – 2 August 1979), was a daughter of Prince Thomas, Duke of Genoa and Princess Isabella of Bavaria.
Princess Amalie Isabella of Bavaria
Princess Amalie Isabella of Bavaria( December 15, 1921 – March 28, 1985) was a member of the Bavarian Royal House of Wittelsbach.
Alfonso III d'Este, Duke of Modena
Alfonso III d' Este( 22 October 1591 – 26 May 1644) was Duke of Modena and Reggio from 1628 to 1629.
He was the husband of Princess Isabella of Savoy, daughter of Charles Emmanuel I, Duke of Savoy and his wife Infanta Catherine Michelle of Spain.
Princess Maria Bona of Savoy-Genoa
Princess Bona of Savoy- Genoa, later Princess Bona of Bavaria( Maria Bona Margherita Albertina Vittoria; 1 August 1896 – 2 February 1971), was a daughter of Prince Thomas, Duke of Genoa and Princess Isabella of Bavaria.
Princess Maria Elisabeth of Bavaria
Princess Maria Elisabeth of Bavaria( 9 September 1914 – 13 May 2011) was the eldest daughter of Prince Franz of Bavaria, third son of Ludwig III of Bavaria.
Isabella Orsini
Princess Isabella Orsini de Ligne de La Trémoïlle( born 2 December 1974) is an Italian actress.

Question: Who is the paternal grandfather of Princess Isabella Of Bavaria?
Answer: Ludwig I of Bavaria