Dietrich III of Limburg-Styrum
Dietrich III of Limburg, count of Limburg zu Stirum (fl. 1347–1391), son of Johann of Limburg.
He married ca. 1353
Johanna von Reifferscheid
and they had issue:
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:
Hermann Georg of Limburg
Hermann Georg of Limburg was count of Limburg and Bronckhorst( 1540 – 1574), son of Georg of Limburg, and count of Limburg and Bronckhorst.
He married in 1554 Maria countess von Hoya und Bruchhausen( died 1612) and they had issue:
Christian Otto of Limburg
Christian Otto von Limburg Stirum, count of Limburg Bronkhorst and Stirum( 1694 – 1749), was a member of the House of Limburg- Stirum and the third reigning monarch from the branch of Limburg- Styrum- Styrum.
Ferdinand III of Limburg Stirum
Ferdinand III of Limburg Stirum was the son of Ferdinand I of Limburg Stirum and Katharina Karoline von Eptingen.
Born in 1753, he died at the age of 15 in 1768.
Wilhelm I of Limburg
Wilhelm I of Limburg, count of Limburg( fl. 1422–1498), son of Eberhard of Limburg.
He married Agnes von Limburg and they had issue:
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.
Johann of Limburg
Johann of Limburg, count of Limburg, gt von Stirum (died before 1364), son of Dietrich II of Isenberg-Limburg.
He married (1st)
Uda von Ravensberg and (2nd)
Margareta von Ahaus, and had four children:
Adolf of Limburg
Adolf of Limburg, count of Limburg( died 1506), son of Wilhelm I of Limburg, count of Limburg.
He married in 1487 Elisabeth von Reichenstein( d. 1529) and they had issue:
Henry of Limburg-Broich
Henry of Limburg- Broich(?- 1446) was the Count of Limburg- Broich from 1439- 1446.
Henry was a son of Count Theodoric IV of Limburg- Styrum.
When Count William I of Limburg- Styrum died in 1439, the County was partitioned with Henry receiving the Lordship of Broich.
Henry died in 1449 and was succeeded by William.

Question: Who is the paternal grandfather of Dietrich Iii Of Limburg-Styrum?
Answer: Dietrich II of Isenberg-Limburg