Question: Who is the maternal grandfather of Maximilian, Margrave Of Baden?

Bernard IV, Margrave of Baden-Durlach
Bernard IV, Margrave of Baden- Durlach( born 1517 – died 20 January 1553) was Margrave of Baden- Pforzheim from 26 September 1552 until his death.
Frederick V, Margrave of Baden-Durlach
Frederick V, Margrave of Baden- Durlach( 6 July 1594, Sulzburg, Hochschwarzwald – 8 September 1659, Durlach) was a German nobleman, who ruled as margrave of Baden- Durlach from 1622 to his death.
He was succeeded by his son Frederick VI, Margrave of Baden- Durlach.
Princess Theodora of Greece and Denmark (1906–1969)
Princess Theodora of Greece and Denmark (30 May 1906 – 16 October 1969) was the second child and daughter of Prince Andrew of Greece and Denmark and Princess Alice of Battenberg, and the second eldest sister of Prince Philip, Duke of Edinburgh.
Herman II, Margrave of Baden
Hermann II of Baden( c. 1060 – 7 October 1130) was the first to use the title Margrave of Baden, after the family seat at Castle Hohenbaden.
This castle is in the present day town of Baden- Baden.
Louis William, Margrave of Baden-Baden
Louis William, Margrave of Baden-Baden (8 April 1655 – 4 January 1707) was the ruling Margrave of Baden-Baden in Germany and chief commander of the Imperial army.
He was also known as "TürkenlouisTurkish Louis") for his many defeats of Turkish armies.
After his death in 1707, his wife, Sibylle of Saxe-Lauenburg, acted as regent of Baden-Baden during the minority of his eldest son, who succeeded him as Margrave of Baden-Baden.
Henry II, Margrave of Baden-Hachberg
Henry II, Margrave of Baden- Hachberg( before 1231 –) was the ruling Margrave of Baden- Hachberg from 1231 to 1289.
Frederick VI, Margrave of Baden-Durlach
Frederick VI, Margrave of Baden- Durlach( 16 November 1617 – 10 or 31 January 1677) was the Margrave of Baden- Durlach from 1659 until his death.
Valerie, Margravine of Baden
Archduchess Valerie of Austria( born 23 May 1941 in Vienna, Ostmark, Germany) is a member of the Tuscan line of the House of Habsburg and an Archduchess of Austria and a Princess of Tuscany by birth.
Through her marriage to Maximilian, Margrave of Baden, Valerie is a member of the House of Zähringen and Margravine consort of Baden.
Maximilian, Margrave of Baden
Maximilian, Margrave of Baden, Duke of Zähringen (Maximilian Andreas Friedrich Gustav Ernst August Bernhard; born 3 July 1933), is the elder son of Berthold, Margrave of Baden and Princess Theodora of Greece and Denmark.
Through his mother, he is the eldest living nephew of Elizabeth II and Prince Philip, Duke of Edinburgh, and is first cousin to Charles, Prince of Wales.
He is the head of the Grand-Ducal House of Baden and the representative of the descent of the Kings of Sweden of the House of Holstein-Gottorp.
Bernhard, Hereditary Prince of Baden
Bernhard, Hereditary Prince of Baden(" Bernhard Max Friedrich August Gustav Ludwig Kraft"; born 27 May 1970 in Schloss Salem, Salem, Baden- Württemberg, Germany) is a German nobleman and heir to the head of the House of Baden.
He is a great- nephew of Prince Philip, Duke of Edinburgh.
He is the eldest son of Maximilian, Margrave of Baden and Archduchess Valerie of Austria.
A commercial lawyer by training, he studied business administration and law in Hamburg and Switzerland.
Prince Bernhard manages the family estates including Staufenberg Castle and the margravine wineries dedicated to preserving the grape variety Müller- Thurgau.
In the years 2000- 2009 he oversaw the transfer of many family assets, including Eberstein Castle and parts of Schloss Salem to the German state in order to stabilise the family's finances.

Answer: Prince Andrew of Greece and Denmark