Princess Luisa Cristina of Savoy
Princess Luisa Cristina of Savoy (27 July 1629 – 12 May 1692) was a Princess of Savoy by birth and the eldest daughter of Victor Amadeus I, Duke of Savoy.
She married her uncle Prince Maurice of Savoy but had no children.
She was the owner of the future "Villa della Regina".
She was a first cousin of Louis XIV of France and Charles II of England.
Yolande Louise of Savoy
Yolande Louise of Savoy( 1487–1499), was a Duchess Consort of Savoy; married to Philibert II, Duke of Savoy.
Princess Maria Pia of Bourbon-Parma
Princess Maria Pia of Bourbon- Parma( née Princess Maria Pia of Savoy; born 24 September 1934) is the eldest daughter of Umberto II of Italy and Marie- José of Belgium.
She is the older sister of Princess Maria Gabriella of Savoy, Vittorio Emanuele, Prince of Naples, and Princess Maria Beatrice of Savoy.
Elena of Montenegro
Princess Elena of Montenegro, or more commonly known as Queen Elena of Italy (8 January 1873 – 28 November 1952) was the daughter of King Nicholas I of Montenegro and his wife, Milena Vukotić.
As wife of Victor Emmanuel III of Italy, she was Queen of Italy from 1900 until 1946, Empress consort of Ethiopia from 1936 until 1941 and Queen consort of the Albanians from 1939 until 1943.
Princess Maria Beatrice of Savoy
Princess Maria Beatrice of Savoy( born 2 February 1943) is the youngest daughter of Italy's last King, Umberto II, and his wife, Queen Marie José.
Princess Maria Anna Victoria of Savoy
Princess Maria Anna Victoria of Savoy (11 September 1683 – 11 October 1763) was the daughter of Prince Louis Thomas of Savoy, Count of Soissons, and Uranie de La Cropte de Beauvais.
Princess Maria Felicita of Savoy
Princess Maria Felicita of Savoy (19 March 1730 – 13 May 1801) was a princess of the House of Savoy, the third daughter of Charles Emmanuel III of Sardinia and his second wife, Polyxena of Hesse-Rotenburg.
Princess Maria Francesca of Savoy
Princess Francesca of Savoy (Maria Francesca Anna Romana; 26 December 1914 – 7 December 2001) was the youngest daughter of Victor Emmanuel III of Italy and Elena of Montenegro.
She was a sister of Umberto II of Italy and of Queen Giovanna of Bulgaria.
Princess Maria Isabella of Savoy-Genoa
Princess Maria Isabella of Savoy- Genoa( born 23 June 1943) is the last surviving male- line descendant of the Dukes of Genoa, a cadet branch of the House of Savoy which ruled Italy from 1861 to 1946.
Thomas Emmanuel, Prince of Savoy-Carignan
Prince Thomas Emmanuel of Savoy,( 8 December 1687 – 28 December 1729), was born a Prince of Savoy and was later Count of Soissons from 1702 till his death.
He was the son of Prince Louis Thomas of Savoy( 1657 – 1702) and Uranie de La Cropte.
The famous general Prince Eugene of Savoy was his uncle.
He married on 24 October 1713 Princess Maria Theresia of Liechtenstein( 1694 – 1772), Duchess of Troppau and had one son.
He became a Knight in the Austrian Order of the Golden Fleece in 1712.
He died in Vienna.

Question: Who is the maternal grandfather of Princess Maria Francesca Of Savoy?
Answer: Nicholas I of Montenegro