Walter III of Châtillon
Walter III of Châtillon( 1166- 1219), also known as Gaucher III of Châtillon, was a French nobleman.
He was a son of Guy II of Châtillon and Adèle of Dreux ..
His brother was Guy III, lord of Chatillon.
In 1196 he married Elisabeth of Saint- Pol, daughter of Hugo IV, Count of Saint- Pol and in 1205, he succeeded his father- in- law as count of Saint- Pol.
Walter and Elisabeth had:
Hugh IV, Count of Saint-Pol
Hugh IV of Saint- Pol( died March 1205 in Constantinople) from the House of Campdavaine, son of Anselm of Saint- Pol, was Count of Saint- Pol from 1174 to his death, and lord of Demotika( Didymoteicho) in Thrace in 1204 – 05.
He participated in the Third and Fourth Crusades.
Anne de Bourbon
Anne de Bourbon (1380 – September 1408) was a daughter of John I, Count of La Marche and his wife Catherine of Vendôme.
She was a member of the House of Bourbon.
Anthony I, Count of Ligny
Anthony I, Count of Ligny( 1450 – 1519) was the youngest son of Louis de Luxembourg, Count of Saint- Pol and his wife, Jeanne de Bar, Countess of Marle and Soissons.
In 1482, he inherited the County of Brienne from his brother Peter II, Count of Saint- Pol.
After the death of Charles of Bourbon in 1510, Anthony inherited the County of Ligny, which thereby fell back to the House of Luxemburg.
John, Count of Saint-Pol
John of Saint-Pol (died 1344) was Count of Saint-Pol between 1317 and 1344.
He was the eldest son of Guy IV, Count of Saint-Pol and Marie of Brittany.
He married in 1319 with Joanna, daughter of John I of Fiennes, and had 2 children:
Marie of Savoy, Countess of Saint-Pol
Marie of Savoy, Countess of Saint- Pol, de Brienne, de Ligny, and Conversano( 20 March 1448 – 1475) was the second wife of Louis de Luxembourg, Count of Saint- Pol, Constable of France.
She was a younger daughter of Louis, Duke of Savoy and Anne de Lusignan, Princess of Cyprus, one of nineteen children.
Joan, Countess of Ligny
Joan, Countess of Saint- Pol and Ligny( d. 18 September 1430, Avignon), called the Demoiselle de Luxembourg, was the daughter of Guy of Luxembourg, Count of Ligny and Mahaut of Châtillon, Countess of Saint- Pol.
At the death of Philip I, Duke of Brabant, she was his nearest living relative on the Saint- Pol side and inherited Saint- Pol and Ligny upon his death on 14 August 1430.
She was living at the time at Beaurevoir, which belonged to her favourite nephew John.
At this time, John held Joan of Arc, whom he had captured, as a prisoner.
The Demoiselle de Luxembourg showed kindness to her and pleaded with her nephew not to sell Joan to the English.
The Demoiselle died shortly thereafter; her fiefs were divided between her senior nephew, the Count of Brienne, who received Saint- Pol, and John, her favourite, who received Ligny.
The Demoiselle is a character in Philippa Gregory's 2011 historical novel" The Lady of the Rivers", which centres on her great- niece Jacquetta of Luxembourg.
Guy IV, Count of Saint-Pol
Guy IV of Châtillon, Count of Saint Pol (– April 6, 1317) was a French nobleman.
He was the son of Guy III, Count of Saint-Pol and Matilda of Brabant.
In 1292, he married Marie of Brittany, daughter of John II, Duke of Brittany and Beatrice of England.
They had eight children:
He held the office of Grand Butler of France.
He was placed in joint command (with Robert VI of Auvergne) of one of the two reserve "battles" of the French troops at the Battle of the Golden Spurs.
He was able to escape when the French were routed by the Flemings, but his brother Jacques and many of his relatives were killed.
Arnold V, Count of Loon
Arnold V de Looz,( died August 22, 1327) was Count of Loon from 1279 to 1323 and Count of Chiny( Arnulf III) from 1299 to 1310.
He was the son of John I, Count of Looz and Mathilde Jülich.
Guy V, Count of Saint-Pol
Guy V of Châtillon, Count of Saint- Pol( d. 1360 in London) was a French nobleman.
He was a member of the House of Châtillon and was the son of Count John of Saint- Pol( d. 1344) and his wife Johanna of Fiennes.
In the Hundred Years' War, he served as a royal commander in the French army.
He fought several battles against the English in Picardy.
He was one of the hostages sent to England under the terms of the Treaty of Brétigny of 1360.
He died of the plague shortly after arriving in London.
Guy was married to Johanna( d. 1392), a daughter of Lord John I of Ligny.
Since they had no children, he was succeeded as Count of Saint- Pol by his sister Mahaut and her husband Guy of Luxembourg- Ligny.

Question: Who is the paternal grandfather of John, Count Of Saint-Pol?
Answer: Guy III, Count of Saint-Pol