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.
Maria II of Portugal
"Dona" Maria II (4 April 1819 – 15 November 1853) "the Educator"  or "the Good Mother" , reigned as Queen of Portugal from 1826 to 1828, and again from 1834 to 1853.
Born in Rio de Janeiro, she was the first child of Emperor Pedro I of Brazil and his first wife, Empress Maria Leopoldina, and thus a member of the House of Braganza.
One of the two surviving children born when Pedro was still heir apparent to Portugal, she inherited Portuguese titles and was placed in the line of succession to the former Portuguese throne, even after becoming a member of the Brazilian Imperial Family, from which she was excluded in 1835 after her definitive ascension to the Portuguese throne.
Abd al-Muttalib
Abd al- Muttalib Shaybah ibn Hashim( c. 497 – 578) was the grandfather of Islamic prophet Muhammad.
Isabel of Viseu
Isabel of Viseu( 1459 – 1521) was a daughter of Infante Fernando, Duke of Viseu and his wife and cousin Infanta Beatrice, Duchess of Viseu.
She was a member of the House of Aviz and later, House of Braganza.
João, Duke of Viseu
Infante João of Viseu( c. 1448 1472) was the older son of Infante Fernando, Duke of Viseu and of his wife Infanta Beatrice of Portugal.
In 1470, following his father's death, he inherited the titles of Duke of Viseu and Duke of Beja, as well as the Lordships of Covilhã and Moura.
He also became Master of the Order of Christ and of the Order of Santiago, becoming also Constable of Portugal.
In July 1472, his uncle, King Afonso V granted him the Moroccan city of Anfa( in Portuguese" Anafé").
He died young and single, without issue.
His brother, Infante Diogo, inherited his titles and estates.
Dinis of Braganza, Count of Lemos
Dinis of Braganza( 1481 – 1516) was the younger son of Fernando II, Duke of Braganza and Isabella of Viseu who was a daughter of Infante Fernando, Duke of Viseu and Beatrice of Portugal.
Afonso, Prince of Portugal (1526)
Afonso, Prince of Portugal was the first son of king John III of Portugal and his queen, Catherine of Austria.
He was the Prince of Portugal but died in the same year he was born, in 1526.
Infante Fernando of Portugal
Infante Fernando of Portugal ("Fernando Maria Luís de Saxe-Coburgo-Gotha e Bragança";
23 July 1846 – 6 November 1861) was the fourth son of Queen Maria II of Portugal and King-consort Fernando II and a member of the House of Braganza.
Fernando, Lord of Serpa
Infante Fernando of Portugal, or Ferdinand in English, was a Portuguese" infante"( prince), son of King Afonso II of Portugal and his wife Urraca of Castile, daughter of Alfonso VIII of Castile.
Fernando was born in the summer of 1217 and was made Lord of Serpa and Lamego in 1223.
It is known that he travelled to Rome in 1237 to beg for a pardon from Pope Gregory IX for his violence against certain clerics.
He died January 19, 1246.
Maria of Portugal, Marchioness of Tortosa
Maria of Portugal (Évora, Kingdom of Portugal, 6 April 1342 – Aveiro, Kingdom of Portugal, after 1375) was a Portuguese "infanta" (princess), first daughter of King Peter I of Portugal and his Queen consort Constanza Manuel.
Maria was born in Évora on 6 April 1342.
In 1354, when she was only twelve years old, she married Fernando of Aragon, marquis of Tortosa, a marriage arranged by her grandfather, King Alfonso IV, to strengthen the alliance between the Kingdom of Portugal and the Crown of Aragon.
Fernando was the son of King Alfonso IV and of his second wife, Eleanor of Castile.
Fernando was murdered by his half-brother Peter IV of Aragon in 1363.
Maria then returned to Portugal where she died in the city of Aveiro after 1375.
She is buried in Monastery of Santa Clara-a-Velha in Coimbra.

Question: Who is the maternal grandfather of Infante Fernando Of Portugal?
Answer: Pedro I