Ferdinand, Count of Flanders
Ferdinand (24 March 1188 – 27 July 1233; Portuguese: "Fernando", French and Dutch: "Ferrand") reigned as "jure uxoris" Count of Flanders and Hainaut from his marriage to Countess Joan, celebrated in Paris in 1212, until his death.
He was born in Coimbra, and he was an Infante of Portugal as the fourth son of King Sancho I of Portugal and Dulce of Aragon.
While on their way to Flanders, Ferdinand and Joan were captured by Joan's first cousin Louis, eldest son of Philip II of France and Joan's aunt Isabella.
Louis' aim was to acquire his dead mother's dowry, a large piece of Flemish territory including Artois, which Joan's father had taken back by force after Isabella's death.
Released after this concession, Joan and Ferdinand soon joined the old allies of her father, King John of England and Emperor
Otto IV, in an alliance against France.
They were decisively defeated at Bouvines in July 1214, where Ferdinand was taken prisoner.
Ferdinand was to remain in French hands for the next 12 years, while Joan ruled alone.
He was released in 1226, by the French regent, Blanche of Castile, after the accession of her son Louis IX of France.
Ferdinand died in Noyon on 27 July 1233.
His and Joan's only child, a daughter named Maria, died childless, and their counties eventually passed to Joan's younger sister, Margaret II.
Ferdinand of Portugal, Duke of Guarda
Ferdinand of Portugal, Duke of Guarda,( 5 June 1507 – 7 November 1534) was a Portuguese" infante"( prince), the son of King Manuel I of Portugal and his second wife, Maria of Aragon.
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.
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.
Archduke Franz Karl of Austria
Archduke Franz Karl Joseph of Austria (17 December 1802 – 8 March 1878) was a member of the House of Habsburg-Lorraine.
He was the father of two emperors:
Franz Joseph I of Austria and Maximilian I of Mexico.
Through his third son Karl Ludwig, he was the grandfather of Archduke Franz Ferdinand of Austria – whose assassination sparked the hostilities that led to the outbreak of World War I – and the great-grandfather of the last Habsburg emperor Karl I.
Maria of Aragon, Queen of Castile
Maria of Aragon was the Queen consort of Castile and Leon as the wife of John II of Castile.
She was the daughter of Ferdinand I of Aragon and Eleanor of Alburquerque.
Archduke Leopold Ferdinand of Austria
Archduke Leopold Ferdinand of Austria (2 December 1868 – 4 July 1935) was the eldest son of Ferdinand IV, Grand Duke of Tuscany, and Alice of Bourbon-Parma.
Dulce of Aragon
Dulce of Aragon (or of Barcelona; ; 1160 – 1 September 1198) was Queen consort to King Sancho I of Portugal.
As the eldest daughter of Ramon Berenguer IV, Count of Barcelona and his wife, Queen Petronila of Aragon, she was the sister of the future King Alfonso II of Aragon.
Her bethrothal to "infante" Sancho, son of Afonso Henriques, the first king of Portugal, was celebrated when she was eleven years old and the marriage in 1174.
Not much is known about her life prior to her arrival in Portugal or of the wedding tokens she received upon her marriage.
"A beautiful and excellent lady, quiet and modest, her personality coinciding with her name," Dulce was used as a commodity to seal an alliance which aimed to "strengthen Portugal and to contain the expansionism of Castile and León" and she played the role that was expected of her as a wife and as the mother of numerous children.
At the same time, the marriage compensated for the broken engagement of her husband's sister, Infanta Mafalda with her brother, the future King Alfonso II of Aragon.
With the death of King Afonso Henriques in 1185, her husband ascended the throne and she became Queen consort of Portugal.
In his first will, executed in 1188, her husband gave her the income from Alenquer, of the lands along the banks of the Vouga River, of Santa Maria da Feira and of Oporto.
Dulce did not live long after the birth of her last two daughters, Branca and Berengaria, probably twins, and died in 1198 probably succumbing to the plague and weakened by the successive childbirths.
She was buried in the Monastery of Santa Cruz in Coimbra.
Eleanor of Aragon, Queen of Portugal
Eleanor of Aragon( 2 May 1402 – 19 February 1445) was queen consort of Portugal as the spouse of Edward I of Portugal and the regent of Portugal as the guardian of her son.
She was the daughter of Ferdinand I of Aragon and Eleanor of Alburquerque.
Isabel of Portugal, Lady of Viseu
Isabella of Portugal( 1364–1395) was the natural daughter of King Ferdinand I of Portugal, from an unknown mother.

Question: Who is Ferdinand, Count Of Flanders's maternal grandfather?
Answer: Ramon Berenguer IV