Joan of Valois, Countess of Beaumont
Joan of Valois (1304–1363) was the daughter of Charles of Valois and his second wife Catherine I of Courtenay, titular empress of Constantinople.
Half sister to Philip VI of Valois, in around 1320 she married Robert III of Artois, Count of Beaumont-le-Roger and seigneur of Conches.
They had five known children:
Robert III of Artois had attempted to recover the title of count of Artois, which had been taken from him by his aunt Mahaut of Artois, but was condemned and exiled in 1331 for making and presenting forged documents in the process of filing against her.
Joan of Valois and their children were therefore imprisoned by order of her half-brother Philip VI.
Jean de Metz
Jean de Metz( also Jean de Nouillonpont)( born c. 1398) was a French nobleman who is known primarily for his role in the exploits of Joan of Arc.
Margaret, Countess of Anjou
Margaret, Countess of Anjou( 1272 – 31 December 1299) was Countess of Anjou and Maine in her own right and Countess of Valois, Alençon, Chartres and Perche by marriage.
Margaret's father was King Charles II of Naples, whilst her husband was Charles of Valois, and her older brother was Saint Louis of Toulouse; her nephew was Charles I of Hungary.
Marie of Valois, Duchess of Calabria
Marie of Valois( 1309 – 23 October 1331), was the eldest daughter of Charles of Valois by his third wife Mahaut of Châtillon.
She was a member of the House of Valois.
One of her five children was Queen Joanna I of Naples.
Charles, Count of Valois
Charles of Valois (12 March 1270 – 16 December 1325), the third son of Philip III of France and Isabella of Aragon, was a member of the House of Capet and founder of the House of Valois, whose rule over France would start in 1328.
Charles ruled several principalities.
He held in appanage the counties of Valois, Alençon and Perche.
Through his marriage to Margaret of Anjou, he became Count of Anjou and Maine.
Through his marriage to Catherine I, titular empress of the Latin Empire, he was titular Latin Emperor of Constantinople from 1301–1307, although he ruled from exile and only had authority over Crusader States in Greece.
The grandson of Louis IX of France, Charles of Valois was a son, brother, brother-in-law and son-in-law of kings or queens (of France, Navarre, England and Naples).
His descendants, the House of Valois, would become the royal house of France three years after his death, beginning with his son Philip VI of France.
Isabella of Brittany
Isabella of Brittany( 1411 – c. 1444) was a daughter of John V, Duke of Brittany, and his wife, Joan of Valois.
Isabella was a member of the House of Dreux.
Joan of Valois, Countess of Hainaut
Joan of Valois (c. 1294 – 7 March 1342) was a Countess consort of Hainaut, Holland, and Zeeland.
She was the second eldest daughter of the French prince Charles, Count of Valois, and his first wife, Margaret, Countess of Anjou.
As the sister of King Philip VI of France and the mother-in-law of Edward III, she was ideally placed to act as mediator between them.
Jean Pasquerel
Jean Pasquerel( c. 1400) was an Augustinian friar( member of the Order of St. Augustine), almoner and confessor of Joan of Arc.
Margaret of Valois, Countess of Blois
Margaret of Valois( 1295–1342) was a French noblewoman.
She was a daughter of Charles, Count of Valois, and his first wife, Margaret, Countess of Anjou.
She was also a sister of King Philip VI of France.
In 1310, she married Guy I, Count of Blois.
They had three children together:
Joan of Valois, Duchess of Alençon
Joan of Valois( 13 September 1409, in Blois – 19 May 1432, in Angers) was the only surviving child of Charles, Duke of Orléans, and Isabella of Valois.
She held the title Duchess of Alençon when married to John II of Alençon.

Question: Who is Joan Of Valois, Countess Of Hainaut's paternal grandfather?
Answer: Philip III of France