Henry IV, Duke of Mecklenburg
Henry IV, Duke of Mecklenburg( 1417 – 9 March 1477) was from 1422 to 1477 Duke of Mecklenburg.
Emma of Blois
Emma of Blois( 950–27 December 1003) was Duchess consort of Aquitaine by marriage to William IV, Duke of Aquitaine.
She ruled Aquitaine as regent for her son, William V, Duke of Aquitaine, from 996 until 1004.
Gerloc
Gerloc (or Geirlaug), baptised in Rouen as Adela (or Adèle) in 912, was the daughter of Rollo, of Normandy, Count of Rouen, and his wife, Poppa of Bayeux.
She was the sister of William I Longsword of Normandy.
In 935, she married William Towhead, the future Count of Poitou and Duke of Aquitaine.
They had two children together before she died on 14 October 962:
William IV, Duke of Aquitaine
William IV (937 – 3 February 994), called Fierebras or Fierebrace (meaning "Proud Arm", from the French "Fier-à-bras" or "Fièrebrace", in turn from the Latin "Ferox brachium"), was the Duke of Aquitaine and Count of Poitou from 963 to his retirement in 990.
William's father, William III, abdicated to the abbey of Saint-Cyprien in Poitiers and left the government to Fierebras.
His mother was Gerloc, the daughter of Duke Rollo of Normandy.
His sister was Adelaide, wife of Hugh Capet, the king against whom William later battled for his duchy.
His early reign was characterised by many wars.
He fought frequently against the counts of Anjou, the first time against Geoffrey Greymantle, who had taken Loudun.
In 988, he went to war with the newly elected king of France, Hugh Capet, whom he refused to recognise.
Capet had been granted Aquitaine by King Lothair before the latter had been reconciled to William's father.
Capet renewed his claim on the great duchy and invaded it that year.
A royal army was defeated on the plain of the Loire Valley.
William sheltered the young Louis, the son of Charles, Duke of Lower Lorraine, the last legitimate Carolingian heir.
He opened the palace of Poitiers to him and treated him as royalty, regarding him as the true heir to the French throne.
In 968, he married Emma or Emmeline, daughter of Theobald I of Blois and Luitgarde of Vermandois.
Their marriage was stormy, in part because of William's indulgence in the pursuit of women and, as a hunting aficionado, wild animals.
She banished his paramours, they separated twice for long periods, and finally he retired to a monastery, as his father had done, leaving Emma to rule Aquitaine in the name of their son William until 1004.
Their second son, Ebles, died sometime after 997.
William IV, Marquess of Montferrat
William IV( c. 1030 – 1100) was the fifth Margrave of Montferrat from 1084.
The date of William's birth is unknown, but it probably took place between 1030 and 1035.
He was the eldest son of Otto II and Constance of Savoy.
Agnes of Aquitaine, Countess of Savoy
Agnes of Aquitaine( c.1052 – after 18 June 1089) was a daughter of William of Poitou, speculated to be William VII, Duke of Aquitaine, whose wife Ermesinde would then have been her mother.
Agnes herself was Countess consort of Savoy and possibly Queen consort of Aragon.
George of Naples
George( date of birth unknown; died 739) was the Duke of Naples for a decade beginning in 729.
Louis X, Duke of Bavaria
Louis X( German: Ludwig X, Herzog von Bayern),( Grünwald, 18 September 1495 – 22 April 1545 in Landshut) was Duke of Bavaria( 1516 – 1545), together with his older brother William IV, Duke of Bavaria.
His parents were Albert IV and Kunigunde of Austria, a daughter of Emperor Frederick III.
Alexandra of Lithuania
Alexandra( died 20 April 1434 in Płock) was the youngest daughter of Algirdas, Grand Duke of Lithuania, and his second wife, Uliana of Tver.
Though Alexandra's exact date of birth is not known, it is thought that she was born in the late 1360s or early 1370s.
In 1387, she married Siemowit IV, Duke of Masovia, and bore him thirteen children.
Theodred II (Bishop of Elmham)
Theodred II was a medieval Bishop of Elmham.
The date of Theodred's consecration unknown, but the date of his death was sometime between 995 and 997.

Question: What is the date of birth of William Iv, Duke Of Aquitaine's mother?