Isabella of Portugal, Duchess of Burgundy
Isabella of Portugal (22 February 1397 – 17 December 1471) was Duchess of Burgundy as the third wife of Duke Philip the Good.
Born a Portuguese "infanta" of the House of Aviz, Isabella was the only surviving daughter of King John I of Portugal and his wife Philippa of Lancaster.
Her son by Philip was Charles the Bold, the last Valois Duke of Burgundy.
Isabella was the regent of the Burgundian Low Countries during the absence of her spouse in 1432 and in 1441–1443.
She served as her husband's representative in negotiations with England regarding trade relations in 1439 and those with the rebellious cities of Holland in 1444.
Maria of Portugal, Duchess of Viseu
Maria of Portugal, Duchess of Viseu (18 June 1521 – 10 October 1577 in Lisbon) was an Infanta of Portugal, the only daughter of King Manuel I of Portugal and Eleanor of Austria.
A noted patron of the arts, Maria's personal wealth rivaled that of the king, her brother (John III of Portugal), making her the richest woman in Portugal and one of the richest in Europe.
Philippa of Lancaster
Philippa of Lancaster (31 March 1360 – 19 July 1415) was Queen of Portugal from 1387 until 1415 by marriage to King John I. Born into the royal family of England, her marriage secured the Treaty of Windsor and produced several children who became known as the "Illustrious Generation" in Portugal.
Isabel of Coimbra
Infanta Isabel of Coimbra( Isabella of Portugal)
( 1 March 1432 – 2 December 1455) was a Portuguese infanta and a queen consort of Portugal as the first spouse of King Afonso V of Portugal.
Isabella of Bourbon
Isabella of Bourbon, Countess of Charolais( 1434 – 25 September 1465) was the second wife of Charles the Bold, Count of Charolais and future Duke of Burgundy.
She was a daughter of Charles I, Duke of Bourbon and Agnes of Burgundy, and the mother of Mary of Burgundy, heiress of Burgundy.
Isabella of France, Dauphine of Viennois
" For other persons named Isabella of France, see Isabella of France( disambiguation)" Isabella of France and Burgundy( 1310 – April 1348) was the daughter of Philip V of France and Joan II, Countess of Burgundy.
Joan III, Countess of Burgundy
Joan III of Burgundy( 1/2 May 1308 – 10/15 August 1347), also known as Joan of France was a reigning Countess of Burgundy and Artois in 1330 – 1349, She was also Duchess of Burgundy by marriage to Odo IV, Duke of Burgundy.
She was the eldest daughter of King Philip V of France and Countess Joan II of Burgundy.
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.
Henry, son of Robert I of Burgundy
Henry of Burgundy (c. 1035 – January 27, 1070/1074), called the Gallant ("le Damoiseau"), was the eldest surviving son and heir of Robert I, Duke of Burgundy, second son of Robert II of France, and his wife, Helie of Semur, granddaughter of Henry I, Duke of Burgundy.
Little is known about his life.
He died shortly before his father and was never duke himself.
The name of Henry's wife is not known, though both Sibylla and Clémence have been suggested.
The first of these derives from an undated obituary from Besançon, Sainte-Etienne, naming "Sibilla, mater ducus Burgundie" (Sibylla, mother of the Duke of Burgundy), it being reasoned that since she is not called duchess, she must have been married to the sole father of a duke who was not a duke himself, Henry.
However, it has been argued by Jean Richard that this is a reference to Sibylla of Burgundy, Duchess of Burgundy, mother of the then-ruling duke, Hugh II.
Richard proposed based on the name's repeated use among the descendants of her son Odo I, Duke of Burgundy that she may have been named Clémence, although Odo's wife had a sister, Clementia of Burgundy, who could have been the inspiration for its use among their descendants.
Based on the use of the byname "Borel" by Odo I, genealogist Szabolcs de Vajay proposed that his mother was the daughter of Berenguer Ramon I, Count of Barcelona and his third wife, Guisle of Lluca, and hence granddaughter of Ramon Borrell, Count of Barcelona, although there is no documentary evidence that this was the case.
Henry's wife died on or after July 6, 1074.
Agnes of France, Duchess of Burgundy
Agnes of France( c. 1260 – 19 December 1327) was a Duchess of Burgundy by marriage to Robert II, Duke of Burgundy.
She served as regent of Burgundy during the minority of her son in 1306 – 1311.

Question: When did Isabella Of Portugal, Duchess Of Burgundy's mother die?
Answer: 19 July 1415