In 1387, Yolande's parents received a marriage proposal for the newly crowned King of Naples, Louis II, through his mother, Marie of Blois.

[2] When she was eleven, Yolande signed a document to disavow any promises made by ambassadors about her marrying Louis II.

As a result of this additional inheritance, Yolande was called the "Queen of Four Kingdoms" - the four apparently Sicily, Jerusalem, Cyprus and Aragon.

In the emerging second phase of the Hundred Years' War, Yolande chose to support the French (in particular the Armagnac party) against the English and the Burgundians.

She had six children, and through her second son René was the grandmother of Margaret of Anjou, the wife of King Henry VI of England.

The French king, Charles VI, was mentally ill and his realm was in a state of civil war between the Burgundians and the Orleanists (Armagnacs).

Fearing the abusive power building behind the Duke of Burgundy, Louis II had Yolande move with her children and future son-in-law, Charles, to Provence in southern France.

In the years 1415 and 1417, the two oldest surviving sons of Charles VI of France died in quick succession: first Louis, then Jean.

She refused Queen Isabeau's orders to return Charles to the French Court; according to Jehan de Bourdigné, when asked she replied , "We have not nurtured and cherished this one for you to make him die like his brothers or to go mad like his father, or to become English like you.

Her young son-in-law, the Dauphin Charles, was exceptionally vulnerable to the designs of the English King, Henry V, and to his older cousin, John the Fearless, the Duke of Burgundy.

Charles' nearest older relatives, the Dukes of Orléans and of Bourbon, had been made prisoners at the Battle of Agincourt and were held captive by the English.

In this struggle, Yolande played a prominent role in surrounding the young Valois king with advisers and servants associated with the House of Anjou.

She manoeuvred John VI, Duke of Brittany, into breaking an alliance with the English, and was responsible for a soldier from the Breton ducal family, Arthur de Richemont, becoming Constable of France in 1425.

The contemporary chronicler Jean Juvenal des Ursins (1433–44), Bishop of Beauvais, described Yolande as "the prettiest woman in the kingdom."

A twentieth-century French author, Jehanne d'Orliac, wrote one of the few works specifically on Yolande, and noted that the duchess remains unappreciated for her genius and influence in the reign of Charles VII.

"She is mentioned in passing because she is the pivot of all important events for forty-two years in France", while "Joan [of Arc] was in the public eye only eleven months."