Louis IX, Duke of Bavaria
Louis IX( also known as Louis the Rich; 23 February 1417 – 18 January 1479),( German:" Ludwig IX, Herzog von Bayern- Landshut") was Duke of Bavaria- Landshut from 1450.
He was a son of Henry XVI the Rich and Margaret of Austria.
Kaoru Hatoyama
After the elections of 2009, she became more widely known as the grandmother of Prime Minister Yukio Hatoyama and his politician brother Kunio Hatoyama.
Joanna Sophia of Bavaria
Joanna Sophia of Bavaria( c. 1373 – 15 November 1410) was the youngest daughter of Albert I, Duke of Bavaria and his first wife Margaret of Brieg.
She was a member of the House of Wittelsbach.
On 13 June 1395, Joanna Sophia married Albert IV, Duke of Austria in Vienna.
The marriage between the two ended a feud between Joanna Sophia's father and Albert's father, Albert III of Austria.
Joanna Sophia's father agreed to the payment of 10,000 Pfennige and he gave Albert III the fortress of Natternberg and the town of Deggendorf.
The marriage produced two children; both of whom survived to adulthood.
They were: Albert would often quarrel with members of Joanna Sophia's family, such as their brother- in- law Wenceslaus, King of the Romans and his half- brother Sigismund, Holy Roman Emperor.
This ended only when Albert died in 1404.
Joanna Sophia arranged marriages for her children.
She made negotiations with Frederick, Duke of Bavaria, to marry her daughter, Margaret to his son, Henry XVI, Duke of Bavaria.
Henry and Margaret married two years after Joanna Sophia's death.
Her son Albert married Elizabeth of Luxembourg, the only child of Emperor Sigismund.
Joanna Sophia died aged thirty- six or thirty- seven in Vienna.
Duchess Marie Gabrielle in Bavaria
Duchess Marie Gabrielle in Bavaria( 9 October 1878 in Tegernsee, Bavaria – 24 October 1912 in Sorrento, Italy) was the youngest daughter of Duke Karl Theodor in Bavaria and his second wife, Infanta Maria Josepha of Portugal.
She married Prince Rupprecht of Bavaria in 1900 but died before he became Crown Prince.
Through her second son Albrecht, Marie Gabrielle was the grandmother of the present Duke of Bavaria, Franz.
Henry XVI, Duke of Bavaria
Henry XVI of Bavaria (1386 – 30 July 1450, Landshut), , since 1393 Duke of Bavaria-Landshut.
He was a son of duke Frederick and his wife Maddalena Visconti, a daughter of Bernabò Visconti.
Maddalena Visconti
Maddalena Visconti (1366 – 17 July 1404) was a daughter of Bernabò Visconti and his wife Beatrice Regina della Scala.
Maddalena was Duchess of Bavaria-Landshut by her marriage to Frederick, Duke of Bavaria.
Tjuyu
Tjuyu( sometimes transliterated as Thuya or Thuyu) was an Egyptian noblewoman and the mother of queen Tiye, and the wife of Yuya.
She is the grandmother of Akhenaten, and great grandmother of Tutankhamun.
Hubba bint Hulail
Hubba bint Hulail was the grandmother of Hashim ibn' Abd Manaf, thus the great- great- great- grandmother of the Islamic" Nabī"( Prophet) Muhammad ibn Abdullah.
Sigismund, Duke of Bavaria
Sigismund of Bavaria (26 July 1439 – 1 February 1501) was a member of the Wittelsbach dynasty.
He ruled as Duke of Bavaria-Munich from 1460 to 1467, and then as Duke of Bavaria-Dachau until his death.
Hannah Arnold
Hannah Arnold, also known as Hannah Waterman King, was the grandmother of Benedict Arnolds children.

Question: Who is the maternal grandmother of Henry Xvi, Duke Of Bavaria?
Answer: Beatrice Regina della Scala