Question: Who is the maternal grandmother of John, Duke Of Touraine?

Knowledge 1: John, Duke of Touraine
John, Dauphin of France and Duke of Touraine (31 August 1398 – 5 April 1417) was the fourth son and ninth child of Charles VI of France and Isabeau of Bavaria.He was born in Paris.After his three elder brothers died, he became Dauphin in 1415.In 1406 he married Jacqueline, heiress of the County of Hainaut, Holland, Zealand, and Frisia.After his marriage to Jacqueline, he was brought up at the castle of Le Quesnoy in Hainaut, at the court of his mother-in-law, Margaret of Burgundy.This arrangement was made between his father and his father-in-law to ensure his safety away from the tulmultous court in Paris, as well as to acquaint him with the lands which he would rule as husband of Jacqueline after her father's death.After the death of his elder brother Louis in December 1415, he became the next Dauphin of France.He died on 5 April 1417 at the age of eighteen.What exactly caused his death is disputed.According to some, he died of the consequences of an abscess to the head, while other sources suggest he had been poisoned.He was buried in Compiègne's Saint-Corneille abbey.His younger brother Charles became dauphin and eventually king. [SEP] Knowledge 2: Isabeau of Bavaria
Isabeau of Bavaria (or Isabelle; also Elisabeth of Bavaria-Ingolstadt; c. 1370 – 24 September 1435) was queen of France between 1385 and 1422.She was born into the House of Wittelsbach as the eldest daughter of Duke Stephen III of Bavaria-Ingolstadt and Taddea Visconti of Milan.At age 15 or 16, Isabeau was sent to the young King Charles VI of France; the couple wed three days after their first meeting.Isabeau was honored in 1389 with a lavish coronation ceremony and entry into Paris.In 1392 Charles suffered the first attack of what was to become a lifelong and progressive mental illness, resulting in periodic withdrawal from government.The episodes occurred with increasing frequency, leaving a court both divided by political factions and steeped in social extravagances.A 1393 masque for one of Isabeau's ladies-in-waiting—an event later known as "Bal des Ardents"—ended in disaster with the King almost burning to death.Although the King demanded Isabeau's removal from his presence during his illness, he consistently allowed her to act on his behalf.In this way she became regent to the Dauphin of France (heir apparent), and sat on the regency council, allowing far more power than was usual for a medieval queen.Charles' illness created a power vacuum that eventually led to the Armagnac–Burgundian Civil War between supporters of his brother, Duke Louis I of Orléans, and the royal dukes of Burgundy.Isabeau shifted allegiances as she chose the most favorable paths for the heir to the throne.When she followed the Armagnacs, the Burgundians accused her of adultery with Louis of Orléans; when she sided with the Burgundians the Armagnacs removed her from Paris and she was imprisoned.In 1407 John the Fearless assassinated Orléans, sparking hostilities between the factions.The war ended soon after Isabeau's eldest son, Charles, had John the Fearless assassinated in 1419—an act that saw him disinherited.Isabeau attended the 1420 signing of the Treaty of Troyes, which decided that the English king should inherit the French crown after the death of her husband, Charles VI.She lived in English-occupied Paris until her death in 1435.Isabeau was popularly seen as a spendthrift and irresponsible philanderess.In the late 20th and early 21st centuries historians re-examined the extensive chronicles of her lifetime, concluding that many elements of her reputation were unearned and stemmed from factionalism and propaganda.
Knowledge 1: Isabeau of Bavaria
Isabeau of Bavaria (or Isabelle; also Elisabeth of Bavaria-Ingolstadt; c. 1370 – 24 September 1435) was queen of France between 1385 and 1422.She was born into the House of Wittelsbach as the eldest daughter of Duke Stephen III of Bavaria-Ingolstadt and Taddea Visconti of Milan.At age 15 or 16, Isabeau was sent to the young King Charles VI of France; the couple wed three days after their first meeting.Isabeau was honored in 1389 with a lavish coronation ceremony and entry into Paris.In 1392 Charles suffered the first attack of what was to become a lifelong and progressive mental illness, resulting in periodic withdrawal from government.The episodes occurred with increasing frequency, leaving a court both divided by political factions and steeped in social extravagances.A 1393 masque for one of Isabeau's ladies-in-waiting—an event later known as "Bal des Ardents"—ended in disaster with the King almost burning to death.Although the King demanded Isabeau's removal from his presence during his illness, he consistently allowed her to act on his behalf.In this way she became regent to the Dauphin of France (heir apparent), and sat on the regency council, allowing far more power than was usual for a medieval queen.Charles' illness created a power vacuum that eventually led to the Armagnac–Burgundian Civil War between supporters of his brother, Duke Louis I of Orléans, and the royal dukes of Burgundy.Isabeau shifted allegiances as she chose the most favorable paths for the heir to the throne.When she followed the Armagnacs, the Burgundians accused her of adultery with Louis of Orléans; when she sided with the Burgundians the Armagnacs removed her from Paris and she was imprisoned.In 1407 John the Fearless assassinated Orléans, sparking hostilities between the factions.The war ended soon after Isabeau's eldest son, Charles, had John the Fearless assassinated in 1419—an act that saw him disinherited.Isabeau attended the 1420 signing of the Treaty of Troyes, which decided that the English king should inherit the French crown after the death of her husband, Charles VI.She lived in English-occupied Paris until her death in 1435.Isabeau was popularly seen as a spendthrift and irresponsible philanderess.In the late 20th and early 21st centuries historians re-examined the extensive chronicles of her lifetime, concluding that many elements of her reputation were unearned and stemmed from factionalism and propaganda. [SEP] Knowledge 2: Philippe Charles, Duke of Valois
Philippe Charles d'Orléans, "petit-fils de France", Duke of Valois (16 July 1664 – 8 December 1666) was a French prince and "Grandson of France".He was styled Duke of Valois at the time of his birth.He was a short lived nephew of Louis XIV.
Knowledge 1: Isabeau of Bavaria
Isabeau of Bavaria (or Isabelle; also Elisabeth of Bavaria-Ingolstadt; c. 1370 – 24 September 1435) was queen of France between 1385 and 1422.She was born into the House of Wittelsbach as the eldest daughter of Duke Stephen III of Bavaria-Ingolstadt and Taddea Visconti of Milan.At age 15 or 16, Isabeau was sent to the young King Charles VI of France; the couple wed three days after their first meeting.Isabeau was honored in 1389 with a lavish coronation ceremony and entry into Paris.In 1392 Charles suffered the first attack of what was to become a lifelong and progressive mental illness, resulting in periodic withdrawal from government.The episodes occurred with increasing frequency, leaving a court both divided by political factions and steeped in social extravagances.A 1393 masque for one of Isabeau's ladies-in-waiting—an event later known as "Bal des Ardents"—ended in disaster with the King almost burning to death.Although the King demanded Isabeau's removal from his presence during his illness, he consistently allowed her to act on his behalf.In this way she became regent to the Dauphin of France (heir apparent), and sat on the regency council, allowing far more power than was usual for a medieval queen.Charles' illness created a power vacuum that eventually led to the Armagnac–Burgundian Civil War between supporters of his brother, Duke Louis I of Orléans, and the royal dukes of Burgundy.Isabeau shifted allegiances as she chose the most favorable paths for the heir to the throne.When she followed the Armagnacs, the Burgundians accused her of adultery with Louis of Orléans; when she sided with the Burgundians the Armagnacs removed her from Paris and she was imprisoned.In 1407 John the Fearless assassinated Orléans, sparking hostilities between the factions.The war ended soon after Isabeau's eldest son, Charles, had John the Fearless assassinated in 1419—an act that saw him disinherited.Isabeau attended the 1420 signing of the Treaty of Troyes, which decided that the English king should inherit the French crown after the death of her husband, Charles VI.She lived in English-occupied Paris until her death in 1435.Isabeau was popularly seen as a spendthrift and irresponsible philanderess.In the late 20th and early 21st centuries historians re-examined the extensive chronicles of her lifetime, concluding that many elements of her reputation were unearned and stemmed from factionalism and propaganda. [SEP] Knowledge 2: Jean Gaston, Duke of Valois
Jean Gaston d'Orléans, "petit-fils de France", Duke of Valois (17 August 1650 – 10 August 1652) was a French Prince and "Grandson of France".He was a member of the House of Orléans.

Answer: Taddea Visconti