Giovanni Nepomucene Ruspoli, 5th Prince of Cerveteri
Giovanni Nepomucene, Principe Ruspoli( June 28, 1807 – November 6, 1876) was the 5th Principe di Cerveteri, 5th Marchese di Riano, 10th Conte di Vignanello, and Prince of the Holy Roman Empire son of Alessandro Ruspoli, 4th Prince of Cerveteri and wife Mariana Gräfin Esterházy de Galántha and ancestor of the Line I of the Principi Ruspoli.
Camillo Ruspoli, 2nd Prince of Candriano
Camillo dei Principi Ruspoli( 10 January 1882 – 5 September 1949), was the 2nd and last Principe di Candriano and Prince of the Holy Roman Empire, son of Emanuele Ruspoli, 1st Prince of Poggio Suasa, and second wife Laura Caracciolo dei Principi di Torella, Duchi di Lavello, Marchesi di Bella.
His maternal uncle, Giuseppe Caracciolo( 1849 – 1920), Patrizio Napolitano, married twice and without issue, was the 1st Prince of Candriano( formerly Marquis of Candriano)( 12 May 1893 – 1 October 1920).
Mario Ruspoli, 2nd Prince of Poggio Suasa
Mario dei Principi Ruspoli (October 16, 1867 –
January 16, 1963) was an Italian prince, son of Emanuele Ruspoli, 1st Prince of Poggio Suasa and first wife Princess Caterina Vogoride-Conachi.
He was the 2nd Prince of Poggio Suasa and Prince of the Holy Roman Empire.
He was responsible for the brief development of Chatsworth, New Jersey as a resort in the early 20th Century.
Marcantonio Mario Dimitri Ruspoli, 3rd Prince of Poggio Suasa
Marcantonio Mario Dimitri dei Principi Ruspoli (November 28, 1926 – August 1, 2003)
was the 3rd Principe di Poggio Suasa and Prince of the Holy Roman Empire, son of Costantino Ruspoli
(Costantino is an eldest son of Mario Ruspoli, 2nd Prince of Poggio Suasa), and wife Elisabeth Catherine Adrienne Marie Anne Comtesse van der Noot d'Assche.
Richard, 4th Prince of Sayn-Wittgenstein-Berleburg
Richard, 4th Prince of Sayn- Wittgenstein- Berleburg was Prince of Sayn- Wittgenstein- Berleburg from 1904 to 1918.
Bartolomeo Ruspoli and Khevenhüller-Metsch
Bartolomeo Ruspoli and Khevenhüller- Metsch, dei principi Ruspoli( October 26, 1800 – 1872) was an Italian aristocrat, Prince of the Holy Roman Empire, son of Francesco Ruspoli, 3rd Prince of Cerveteri and second wife Leopoldina Countess von Khevenhüller- Metsch.
He had four brothers, among others, Alessandro Ruspoli, 4th Prince of Cerveteri, and Camillo Ruspoli, Duke of Sueca.
He was colonel of the Piedmontese army, in which he participates in the wars of the Italian resurgence.
Paralyzed from below waist by the blast of a grenade, he continued to participate in wheelchair battles pushed by his assistant.
Bartolomeo is the ancestor of the Line III of the Princes Ruspoli.
His son Emanuele Ruspoli was named first prince of Poggio- Suasa after participating in the Italian unification and being the first Mayor of the Italian Rome.
He was the grandfather of Donna Emanuella de Dampierre Ruspoli, Duchess of Segovia and Duchess of Anjou by her marriage to Infante Don Jaime, son of Alfonso XIII of Spain.
Emanuele is the founder of the third Ruspoli line: The Princes of Poggio- Suasa.
Costantino Mario Ruspoli, 4th Prince of Poggio Suasa
Constantino Mario dei Principi Ruspoli (born 29 June 1971), son of Marcantonio Mario Dimitri Ruspoli, 3rd Prince of Poggio Suasa, and his second wife Gleide Portela Chagas (1935–2002), is the 4th Principe di Poggio Suasa and Prince of the Holy Roman Empire.
Emanuele Ruspoli, 1st Prince of Poggio Suasa
Emanuele Francesco Maria dei Principi Ruspoli, 1 Prince of Poggio Suasa (December 30, 1837 – November 29, 1899)
was an Italian and a Holy Roman Empire prince who twice served as the Mayor of Rome.
Francesco Alvaro Maria Giorgio Ruspoli, 1st Duke of Morignano
" Don" Francesco Alvaro Maria Giorgio dei Principi Ruspoli( April 19, 1891 – March 2, 1970) was an Italian nobleman, the 1st Duca di Morignano, Nobile di Viterbo e di Orvieto, Patrizio Romano and Prince of the Holy Roman Empire.
Born in Rome, he was the son of Emanuele Ruspoli, 1st Prince of Poggio Suasa and third wife Josephine Mary Beers- Curtis.
Augusto Ruspoli, 11th Duke of Fiano
Augusto Ruspoli- Ottoboni, dei Principi Ruspoli( Rome, September 8, 1880 – Rome, 1912), was an Italian aristocrat and son of Mario Ruspoli and Costanza Boncompagni- Ludovisi- Ottoboni.
Mario was the youngest son of Augusto Ruspoli, who was the youngest son of Alessandro Ruspoli, 4th Prince of Cerveteri.
And Costanza was daughter of Marco Boncompagni Ludovisi Ottoboni, 10th Duke of Fiano.
Augusto inherited the title of his maternal grandfather, becoming the 11th Duke of Fiano.
He was also Patrizio Romano, Noble of Viterbo and Orvieto and Prince of the Holy Roman Empire.
He died unmarried and without issue and was succeeded in the title by his cousin Cesare Ottoboni.

Question: Who is Costantino Mario Ruspoli, 4Th Prince Of Poggio Suasa's paternal grandfather?