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.
Charles the Bald
Charles ΙΙ the Bald (13 June 823 – 6 October 877) was the king of West Francia (843–877), king of Italy (875–877) and emperor of the Carolingian Empire (875–877).
After a series of civil wars during the reign of his father, Louis
the Pious, Charles succeeded, by the Treaty of Verdun (843), in acquiring the western third of the Carolingian Empire.
He was a grandson of Charlemagne and the youngest son of Louis the Pious by his second wife, Judith.
Judith of Brittany
Judith of Brittany, also called Judith of Rennes( 982–1017), was Duchess of Normandy from until her death.
Richilde, Countess of Hainaut
Richilde, Countess of Mons and Hainaut( – 15 March 1086), was a ruling countess of Hainaut from c. 1050 until 1076, in co-regency with her husband Baldwin VI, Count of Flanders and son Baldwin II, Count of Hainaut.
She was also countess consort of Flanders by marriage to Baldwin VI, Count of Flanders.
She served as regent of Flanders during the minority of her son Arnulf III, Count of Flanders in 1070- 1071.
Judith of Flanders
Judith of Flanders (or Judith of France) (843 – c. 870) was queen consort of Wessex and countess consort of Flanders.
She was the eldest daughter of the West
Frankish King and later Holy Roman Emperor Charles the Bald and his wife Ermentrude of Orléans.
Through her marriages to two Kings of Wessex, Æthelwulf and Æthelbald, she was twice a queen.
Her first two marriages were childless, but through her third marriage to Baldwin, she became the first Countess of Flanders and an ancestor of later Counts of Flanders.
One of her sons by Baldwin married Ælfthryth, a daughter of Æthelbald's brother, Alfred the Great.
She was also an ancestor of Matilda of Flanders, the consort of William the Conqueror, and thus of later monarchs of England.
Margaret I, Countess of Flanders
Margaret I of Flanders( c. 1145- died 15 November 1194) was ruling countess of Flanders" suo jure" from 1191 to her death.
She was the daughter of Thierry, Count of Flanders, and Sibylla of Anjou, and the heiress of her childless brother, Philip of Flanders.
Margaret I, Countess of Burgundy
Margaret I( 1310 – 9 May 1382), was a ruling Countess Palatine of Burgundy and Artois from 1361 and 1382.
She was also countess of Flanders, Nevers and Rethel by marriage to Louis I, Count of Flanders, and regent of Flanders during the minority of her son Louis II, Count of Flanders in 1346.
Judith of Hohenstaufen
Judith of Hohenstaufen, also known as" Judith of Hohenstaufen" or" Judith of Swabia"( – 7 July 1191), a member of the Hohenstaufen dynasty, was Landgravine of Thuringia from 1150 until 1172 by her marriage with the Ludovingian landgrave Louis II.
She was baptized as" Judith", but was commonly called" Jutta" or" Guta".
Sometimes the Latinate form" Clementia" was used, or" Claritia" or" Claricia".
Baldwin V, Count of Flanders
Baldwin V of Flanders( c. 1012 – 1 September 1067) was Count of Flanders from 1035 until his death.
He was the son of Baldwin IV, Count of Flanders, who died in 1035.
Arnulf I, Count of Flanders
Arnulf of Flanders( c. 890 – 27 March 965), called the Great, was the first Count of Flanders.

Question: Who is Judith Of Flanders's paternal grandfather?
Answer: Louis the Pious