Adolph I, Duke of Cleves
Adolph I of Cleves( 2 August 1373 – 23 September 1448) was the second Count of Cleves and the fourth Count of Mark.
Johann, Count of Cleves
Johann was last Count of Cleves, from 1347 through 1368.
Upon his death in 1368, the counties of Cleves and Count of Mark were united.
Johann was the youngest son of Dietrich VII, Count of Cleves and his second wife Margaret of Habsburg.
He succeeded in 1347 his brother Dietrich VIII, Count of Cleves who had died without sons.
He married Mechteld of Guelders( † 1384), daughter of Reginald II, Duke of Guelders, but the marriage remained childless.
After his death, the County of Cleves went to Adolf III of the Marck and so to the Counts of Marck.
Dietrich III, Count of Cleves
Dietrich III was Count of Cleves from 1172 through 1188.
He was the son of Dietrich II, Count of Cleves, and Adelaide, daughter of Gebhard III of Sulzbach.
The County of Cleves  was a comital polity of the Holy Roman Empire in present Germany (part of North Rhine-Westphalia) and the Netherlands (parts of Limburg, Noord-Brabant and Gelderland).
Its rulers, called counts, had a special and privileged standing in the Empire.
The County of Cleves was first mentioned in the 11th century.
In 1417, the county became a duchy , and its rulers were raised to the status of Dukes.
Its history is closely related to that of its neighbours: the Duchies of Jülich, Berg and Guelders and the County of Mark.
In 1368, Cleves and Mark were united.
In 1521 Jülich, Berg, Cleves and Mark formed the United Duchies of Jülich-Cleves-Berg.
The territory was situated on both sides of the river Rhine, around its capital Cleves and roughly covering today's districts of Cleves, Wesel and the city of Duisburg.
According to the German, Dutch and French Wikipedia there was only one Dietrich between 1172 and 1198.
This Dietrich was the son of Dietrich II and Adelaide of Sulzbach and was married to Margaret of Holland.
This would make Dietrich III and Dietrich IV the same person.
Adolph II of the Marck
Adolph II of the Marck( died 19/20 October 1347, Fröndenberg) was Count of the Marck.
He was the eldest son of Engelbert II of the Mark and Mechtild of Arenberg.
Adolph was betrothed to Irmgard of Cleves, daughter of Otto, Count of Cleves and his( second) wife Mechtild of Virneburg.
After obtaining a papal dispensation Adolf was allowed to marry Margaret of Cleves, the daughter of Dietrich VIII, Count of Cleves and Margaret of Guelders.
Adolph and Margaret of Cleves had seven children:
Dietrich V, Count of Cleves
Dietrich V was Count of Cleves from 1201 through 1260.
Dietrich was born about 1185 as the son of Dietrich IV, Count of Cleves and Margaret of Holland.
Possibly Dietrich V succeeded in 1198, under regency of Arnold II.
In 1234, he participated in the Stedinger Crusade.
Dietrich IV, Count of Cleves
Dietrich IV was Count of Cleves from 1188 through 1198.
The County of Cleves was a comital polity of the Holy Roman Empire in present Germany( part of North Rhine- Westphalia) and the Netherlands( parts of Limburg, Noord- Brabant and Gelderland).
Its rulers, called counts, had a special and privileged standing in the Empire.
The County of Cleves was first mentioned in the 11th century.
In 1417, the county became a duchy, and its rulers were raised to the status of Dukes.
Its history is closely related to that of its neighbours: the Duchies of Jülich, Berg and Guelders and the County of Mark.
In 1368, Cleves and Mark were united.
In 1521 Jülich, Berg, Cleves and Mark formed the United Duchies of Jülich- Cleves- Berg.
The territory was situated on both sides of the river Rhine, around its capital Cleves and roughly covering today's districts of Cleves, Wesel and the city of Duisburg.
He married Margaret, daughter of Floris III, Count of Holland, and his wife Ada of Huntingdon.
According to the German, Dutch and French Wikipedia there was only one Dietrich between 1172 and 1198.
This Dietrich was the son of Dietrich II and Adelaide of Sulzbach and was married to Margaret of Holland.
This would make Dietrich III and Dietrich IV the same person.
Eberhard of Limburg
Eberhard of Limburg, count of Limburg( died before 1426), son of Dietrich III of Limburg, count of Limburg.
He married Ponzetta von Saffenberg and they had issue:
Dietrich VIII, Count of Cleves
Dietrich VIII( – 7 July 1347) was a German nobleman.
He was Count of Cleves from 1310 through 1347.
Dietrich was the son of Dietrich VII, Count of Cleves and his second wife Margaret of Habsburg.
He succeeded in 1310 his half- brother Otto, Count of Cleves who had died without sons.
Dietrich VIII married twice:
He was succeeded by his brother John.< br>
When his brother also died without a son, the County of Cleves went to his daughter's son Adolph III of the Marck and so to the Counts of Marck.
Dietrich II, Count of Cleves
Dietrich II was Count of Cleves from 1147 through 1172, son of Arnold I, Count of Cleves and Ida, the daughter of Godfrey I, Count of Louvain.
The County of Cleves  was a comital polity of the Holy Roman Empire in present Germany (part of North Rhine-Westphalia) and the Netherlands (parts of Limburg, Noord-Brabant and Gelderland).
Its rulers, called counts, had a special and privileged standing in the Empire.
The County of Cleves was first mentioned in the 11th century.
In 1417, the county became a duchy), and its rulers were raised to the status of Dukes.
Its history is closely related to that of its neighbours: the Duchies of Jülich, Berg and Guelders and the County of Mark.
In 1368, Cleves and Mark were united.
In 1521 Jülich, Berg, Cleves and Mark formed the United Duchies of Jülich-Cleves-Berg.
The territory was situated on both sides of the river Rhine, around its capital Cleves and roughly covering today's districts of Cleves, Wesel and the city of Duisburg.
He married Adelaide, the daughter of Gebhard III of Sulzbach and Matilda of Bavaria, they had the following issue:
John I, Duke of Cleves
John I, Duke of Cleves, Count of Mark( 16 February 1419 – 5 September 1481) was Duke of Cleves and Count of Mark.

Question: Who is the paternal grandfather of Dietrich Iii, Count Of Cleves?
Answer: Arnold I, Count of Cleves