John II, Count of Blois
John II of Châtillon( died 1381, in Valenciennes), second son of Louis I of Châtillon and Jeanne of Avesnes, was count of Blois and lord of Avesnes from 1372 to 1381.
In February 1372, he married Mathilde of Guelders( d. 1384), the daughter and co-heir of Duke Reginald II of Guelders, and became Lord of Schoonhoven and Gouda.
He spent most of his career trying to seize Guelders from Mathilde's nephew William I of Guelders and Jülich.
Reinald IV, Duke of Guelders and Jülich
Reinald IV, Duke of Guelders and Jülich aka Reginald IV (– 25 June 1423) was the son of William II, Duke of Jülich and Maria of Guelders, daughter of Reinald II, Duke of Guelders.
Reinald IV became the second Duke of Guelders and Jülich upon his brother William's death in 1402 without heirs.
Reinald, in conjunction with the Wittelsbach Counts of Holland, Hainaut and Zeeland, tried in vain to slow the emergence of Burgundy in the Netherlands area and in 1406 was unable to enforce old claims against Burgundy to Brabant-Limburg.
He allied himself with Rupert, King of Germany, supporting his coronation in Aachen and remained closely connected with the House of Orléans.
In 1407, Reinald supported his brother-in-law, John of Arkel, against the Dutch and in 1409 received the city of Gorinchem from John.
This started a new feud with Holland which ended in 1412 when Reinald ceded Gorinchem for a large sum of money.
He also conceded the city of Emmerich as a result of an earlier promise to the Duke of Cleves.
Reinald led the traditional feuds of his House, particularly those against the Bishops of Utrecht and against Holland and Friesland.
He occupied Arkel, but in 1422 he was forced to seek peace and return all of his conquests.
Reinald also stood against the House of Cleves in the Niederrhein area and maintained a lot of influence over Guelders.
On 5 May 1405, Reinald married Marie of Harcourt, daughter of John VI, Count of Harcourt.
Reinald died near Arnhem on 25 June 1423 and was buried at Kloster Monkhuizen.
As Reinald died without legitimate issue, the Duchy of Jülich descended to Adolf, Duke of Berg, son of Reinald's cousin William VII of Jülich, 1st Duke of Berg.
In 1426, Reinald's widow married Adolf's son Rupert, but he died in 1431 without heirs and the Duchy of Jülich-Berg then descended to Adolf's nephew Gerhard.
The Duchy of Guelders descended to Reinald's great-nephew, Arnold of Egmond, although the House of Jülich fought unsuccessfully against the House of Egmond for this title.
Maria, Duchess of Guelders
Marie of Guelders( † May 12, 1405) was one of two pretenders to the title of Duchess of Guelders and Countess of Zutphen on behalf of her son during the War of the Guelderian Succession from 1371 to 1379.
The war began after the deaths of her brothers, Reginald III of Guelders and Edward of Guelders.
Edward died from wounds received at the Battle of Baesweiler, and Reginald, who was known as the fat, died months later.
Succession was also claimed by Marie's sister, Mathilda, whose side was called the" Heeckerens" and were led by Frederik van Heeckeren van der Eze( 1320- 1386).
Her party was called the" Bronckhorsters" and was led by Gijsbert V van Bronckhorst( 1328- 1356).
Upon victory of her party, the title of Duke of Guelders went to her son, William.
Marie was daughter of Reginald II, Duke of Guelders and Sophie Berthout, lady of Malines.
On December 25, 1362, she married William II, Duke of Jülich( † 1393).
They had three children:
William II, Duke of Jülich
William II, Duke of Jülich (– 13 December 1393) was the second Duke of Jülich and the sixth William in the House of Jülich.
He was the second son of William I of Jülich and Joanna of Hainaut.
William was co-ruler from 1343.
He quarreled greatly with his father and imprisoned him from 1349-1351.
He tried for many years in Holland-Zeeland to enforce claims against the House of Wittelsbach but failed.
When his father died in 1361, William became the second Duke of Jülich, his elder brother Gerhard having predeceased their father.
He led the traditional feuds of the House of Jülich and lost Kaiserswerth and Zülpich, among others.
William intervened in favor of Edward in the catastrophic war of succession between his brothers-in-law Reinald and Edward for control of the Duchy of Guelders.
He took part in the 1371 Battle of Baesweiler (in which Edward was mortally wounded) and captured Wenceslaus I, Duke of Luxembourg.
His brother-in-law Reinald died later in 1371 and as neither Reinald nor Edward left heirs, another fight for the succession of Guelders arose between William and his wife Maria (sister to Reinald and Edward) and Maria's sister Mathilde, wife of John II, Count of Blois.
In 1377, Emperor Charles IV granted Guelders to William's son William, but the title was not secured until 1379.
Among other territories, William acquired Monschau-Montjoie, Randerath and Linnich.
Otto I, Count of Guelders
Otto I of Guelders( 1150 – 1207) was a Count of Guelders and Zutphen from 1182 until his death in 1207.
He was a son of Duke Hendrik of Guelders and Agnes of Arnstein.
He married Richardis of Bavaria in 1184.
Richardis was a daughter of Otto I Wittelsbach, Duke of Bavaria.
Gerard III, Count of Guelders
Gerard III of Guelders( 1185 – 22 October 1229) was the Count of Guelders and Zutphen from 1207 until his death in 1229.
He was a son of Count Otto I of Guelders, and is sometimes called Gerard IV or Gerard V.
He married Margaretha of Brabant, the daughter of Duke Hendrik I of Brabant, in 1206.
Reginald III, Duke of Guelders
Reginald III of Guelders( or" Renaud", known as" The Fat")( 13 May 1333 – 4 December 1371) was Duke of Guelders and Count of Zutphen from 1343 to 1361, and again in 1371.
He was the son of Reginald II of Guelders and of Eleanor of Woodstock, daughter of Edward II of England.
With the death of his father in 1343, his mother held the regency until 1344.
From 1350, his brother Edward asserted his rights and a quarrel of succession broke out between the two brothers until 1361.
Reginald was overcome in Tiel and was imprisoned in the castle of Nijenbeek.
There he became so large that he could not have left, even if the door had remained open—hence his appellation" The Fat".
Edward died on 24 August 1371, having been mortally wounded in the Battle of Baesweiler, and Reginald was released( according to the legend, the walls had to be cut away so he could leave); he held the ducal throne for only a short period, dying a few months later.
He was buried at Graefenthal Abbey.
As he did not have a legitimate child, the succession passed to his sisters: Mathilde( also, Machteld), who was married to John II, Count of Blois, and Maria, wife of William II of Jülich and mother to William I of Guelders and Jülich, on whose behalf she claimed the throne of Guelders.
The sisters and their respective followers( the" Heeckerens", from the party led by families of Van Heeckeren and their relatives, the Van Rechterens, supported Mathilde, while the faction known as the" Bronkhorsters" followed Maria) fought for the duchy of Guelders in the War of the Succession of Guelders.
Katherine of Bavaria
Katherine of Bavaria( c. 1361–1400 AD, Hattem), was the eldest child of Albert I, Duke of Bavaria and his first wife Margaret of Brieg.
She was Duchess of Guelders and Jülich by her marriage to William I of Guelders and Jülich.
Reginald II, Duke of Guelders
Reginald II of Guelders, called" the Black"( c. 1295 – 12 October 1343), was Count of Guelders, and from 1339 onwards Duke of Guelders, and Zutphen, in the Low Countries, from 1326 to 1343.
He was the son of Reginald I of Guelders and Marguerite of Flanders.
William I of Guelders and Jülich
William I of Guelders and Jülich KG( 5 March 1364 – 16 February 1402, Arnhem) was Duke of Guelders, as William I, from 1377 and Duke of Jülich, as William III, from 1393.
William was known for his military activities, participating in the Prussian crusade five times and battling with neighbors in France and Brabant throughout his rule.
His allies included Holy Roman Emperors, Charles IV and Wenceslaus, Richard II of England, and Conrad Zöllner von Rothenstein, the Grand Master of the Teutonic Knights.
During his reign the duchies of Guelders and Jülich were temporarily unified.

Question: Who is the paternal grandmother of Reinald Iv, Duke Of Guelders And Jülich?
Answer: Joanna of Hainaut