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:
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.
Beatrice of Coimbra
Infanta Beatrice of Coimbra( 1435 – 1462) was the 5th child of Infante Peter, Duke of Coimbra, and Isabella of Urgell.
After the battle of Alfarrobeira, where her father's army was defeated by the Portuguese royal army, she left the country and took refuge in Burgundy, under her aunt ’s protection: Isabella of Portugal was married to Duke Philip III the Good.
In 1453, Beatrice married Adolph of Cleves, Lord of Ravenstein, nephew of the Duke Philip III the Good.
They had issue:
She died in Bruges of suspected poisoning in 1462.
Margaret of Cleves, Duchess of Bavaria-Munich
Margaret of Cleves( 1416–1444) was a German noblewoman.
She was the eldest daughter of Adolph I, Duke of Cleves and his second wife Marie of Burgundy.
She married
Anna van Bourgondië
Anna van Bourgondië( 1435- 1508), was the illegitimate daughter of Philip the Good and Jacqueline van Steenberghe.
She was a governess, supervising the education of Mary of Burgundy.
She married Adriaan van Borssele and Adolph of Cleves, Lord of Ravenstein.
She is known for her building projects on her domains.
Philip of Cleves, Lord of Ravenstein
Philip of Cleves( 1459 in Le Quesnoy – 28 January 1528 in Wijnendale Castle), Lord of Ravenstein, Wijnendale and Enghien, was a nobleman from the Low Countries and army commander, first for Maximilian of Austria, then for Flemish rebels and the kingdom of France.
Karl Harst
Karl Harst( fl. 1540) was a sixteenth- century diplomat from the German Duchy of Cleves.
He was the Duke of Cleves' representative in London during the marriage of Henry VIII of England and his fourth wife, Anne of Cleves.
Elisabeth of Cleves, Countess of Schwarzburg-Blankenburg
Elisabeth of Cleves was the daughter of Adolph I, Duke of Cleves and Marie of Burgundy, Duchess of Cleves.
She married Count Henry XXVI of Schwarzburg- Blankenburg, on July 15, 1434.
Adolph of Cleves, Lord of Ravenstein
Adolph of Cleves, Lord of Ravenstein
(1425–1492) was the youngest son of Adolph I, Duke of Cleves, and of his wife Marie of Burgundy, a sister of Philip the Good, Duke of Burgundy.
Mary of Burgundy, Duchess of Cleves
Mary of Burgundy, Duchess of Cleves (1393 – 30 October 1466) was the second child of John the Fearless and Margaret of Bavaria, and an elder sister of Philip the Good.
Born in Dijon, she became the second wife of Adolph, Count of Mark in May 1406.
He was made the 1st Duke of Cleves in 1417.
They were the grandparents of King Louis XII of France and the great-grandparents of John III, Duke of Cleves, father of Anne of Cleves, who was fourth Queen consort of Henry VIII of England.
By their daughter, Catherine, they were ancestors of Mary, Queen of Scots.
The Duke and Duchess of Cleves lived at Wijnendale Castle in West Flanders.
She died in Cleves in present-day Monterberg, Kalkar.

Question: Who is the maternal grandfather of Adolph Of Cleves, Lord Of Ravenstein?
Answer: John the Fearless