Theobald V, Count of Blois
Theobald V of Blois( 1130 – 20 January 1191), also known as Theobald the Good, was Count of Blois from 1151 to 1191.
Alix of France
Alix of France( July – August 1150 – 1197/1198) was countess consort of Blois by marriage to Theobald V, Count of Blois.
She was regent of Blois during the absence of her spouse in 1190- 1191, and regent during the minority of Louis I, Count of Blois from 1191 until 1197.
Theobald II of Blois
Theobald II, Count of Blois( Thibaut II; c. 985 – 11 July 1004) was the eldest son and heir of Odo I, Count of Blois, and Bertha of Burgundy.
The stepson of Robert II of France, he became Count of Blois, Châteaudun, Chartres and Reims after the death of his father in 996.
Theobald II left no heirs; on his death, he was succeeded by his younger brother, Odo II, Count of Blois.
Gerard, Count of Rieneck
Gerard( died 1216), Count of Rieneck, son of Gerard, Count of Loon, and Adelaide of Gelderland, daughter of Henry I, Count of Guelders, and Agnes of Arnstein, daughter of Louis III of Arnstein.
Virtually nothing is known about his life other than his children who succeeded their uncles as Counts of Looz.
Gerard married Cunegonde von Zimmern, daughter of Sibodo III, Count of Zimmern.
Gerard and Cunegonde had five children: Gerard was succeeded as Count of Rieneck by his brother Arnold.
Louis III, Count of Löwenstein
Louis III, Count of Löwenstein( 17 February 1530 in Vaihingen † 13 March 1611 in Wertheim) was the ruling Count of Löwenstein- Wertheim from 1571 until his death.
Hugh I, Count of Blois
Hugh I, Count of Blois, also known as" Hugh I of Châtillon"( c.1198 – 9 April 1248) was Count of Blois from 1230 to 1241, and Count of Saint Pol( as Hugh V) from 1226 to 1248.
Hugh was son of Gaucher III of Châtillon and Elisabeth( 1180 – 1212), daughter of Hugo IV, Count of Saint- Pol.
He married Agnes of Bar- le- Duc, daughter of Thibaut I of Bar- le- Duc and Hermesend of Bar-sur- Seine, in 1216.
By 1225, Agnes was dead and Hugh married Marie.
In 1226, Hugh married Marie of Avesnes, daughter of Walter II of Avesnes and Margaret of Blois.
They had 5 children:
Through his marriage Hugh became the first count of Blois from the house of Châtillon.
It marked the end of the first dynasty of Blois that lasted over 400 years.
After the death of Marie, Hugh married Mahaut, sister of Baldwin III, Count of Guînes.
In 1226 the Cisterian nunnery Pont-aux- Dames in Couilly was founded by Hugh.
Later Hugh, with the assistance of Philip Mécringes, founded a Cistercian nunnery at Troissy called" L'Amour- Dieu" in 1232.
Hugh intended to follow the pious king Louis IX when he started on the Seventh Crusade, but he died in 1248.
Theobald III, Count of Blois
Theobald III of Blois( French:" Thibaut")( 1012–1089) was count of Blois, Meaux and Troyes.
He was son of Odo II, Count of Blois and Ermengarde of Auvergne.
Louis III, Count of Blois
Louis III of Châtillon (died 1372), son of Louis II, Count of Blois and Jeanne of Hainault, was count of Blois and lord of Avesnes 1346–1372, and count of Soissons 1346–1367.
After the Battle of Poitiers, he had to send his brother Guy as a hostage to London, and ultimately sold Soissons to Enguerrand VII de Coucy to ransom him.
Henry, Count of Looz
Henry( d. 2 August 1218), Count of Looz and Count of Duras, son of Gérard II, Count of Looz, and Adelaide of Gelderland, daughter of Henry I, Count of Guelders, and Agnes of Arnstein, daughter of Louis III of Arnstein.
Henry was Canon of St. Lambert in Liège, Provost of the Franciscans in Maastricht, and Provost of St. Alexander in Aschaffenburg.
Henry was Count of Looz for a few days in 1218, but died of poisoning.
He married Mechtild, daughter of Frederick III, Count of Vlanden.
Henry and Mechtild had one daughter:
He was succeeded as Count of Looz by his brother Arnold, and was the last recorded Count of Duras.
Jeanne of Hainault
Jeanne (or Johanna) of Hainault (1323 – December 1350) was ruling Countess of Soissons from 1344 until 1350.
She was a daughter of John of Beaumont, lord of Beaumont and Margaret of Soissons.
She succeeded her mother in 1344 as Countess of Soissons.
Jeanne first married Louis II, Count of Blois.
Together they had three sons:
Louis II died in 1346 at the battle of Crécy and Jeanne remarried to William I, Marquis of Namur.
They had no children.
She died in 1350 from the Black Death.

Question: Who is the maternal grandfather of Louis Iii, Count Of Blois?
Answer: John of Beaumont