Louis V, Landgrave of Hesse-Darmstadt
Louis V of Hesse-Darmstadt (24 September 1577 – 27 July 1626) was the Landgrave of Hesse-Darmstadt from 1596 to 1626.
He was born on 24 September 1577 as the son of George I, Landgrave of Hesse-Darmstadt and Magdalene of Lippe.
In 1604 he inherited a part of Hessen-Marburg after the death of Louis IV of Hesse-Marburg who was childless.
The other half went to Maurice of Hesse-Kassel (or Hesse-Cassel), but since Maurice was a Calvinist, Ludwig claimed a right on the whole of Hesse-Marburg.
Lutheran professors of the University of Marburg who refused to convert to Calvinism founded in 1607 the University of Gießen which was named "Ludoviciana".
This led to a conflict during the Thirty Years' War, between Louis V, who stood on the side of the Emperor, and Maurice, who was on the side of the Protestants.
Hesse-Darmstadt suffered severely from the ravages from the Swedes during the conflict.
The Landgrave died in 1626 and he was succeeded by George II, Landgrave of Hesse-Darmstadt.
In 1722, Johann Georg Liebknecht, an astronomer at the University of Gießen, named a star, which he thought was a planet, Sidus Ludoviciana after Ludwig V.
Charles I, Landgrave of Hesse-Philippsthal
Charles I, Landgrave of Hesse- Philippsthal( 23 September 1682 – 8 May 1770) was a member of the House of Hesse and Landgrave of Hesse- Philippsthal from 1721 until his death.
Philip, Landgrave of Hesse-Philippsthal
Philip of Hesse- Philippsthal( 14 December 1655 – 18 June 1721) was the son of William VI, Landgrave of Hesse- Kassel and Hedwig Sophia of Brandenburg.
He was the first landgrave of Hesse- Philippsthal from 1663 to 1721 and the founder of the fifth branch of the house of Hesse.
Louis IV, Landgrave of Hesse-Marburg
Landgrave Louis IV of Hesse-Marburg (27 May 1537 – 9 October 1604) was the son of Landgrave Philip I of Hesse and his wife Christine of Saxony.
After the death of his father in 1567, Hesse was divided among his sons and Louis received Hesse-Marburg (Upper Hesse) including Marburg and Giessen.
Louis received his education at the court of Duke Christoph of Württemberg.
He had the Marburg Castle renovated by his architect Ebert Baldewein.
Wanting to enlarge his territory peacefully, he bought parts of the Fuldischen Mark in 1570 from the counts of Nassau-Saarbrücken and the rest in 1583 from the count of Nassau-Weilburg.
On 10 May 1563 he married Hedwig of Württemberg and his second marriage was to Marie, Countess of Mansfeld.
When he died in 1604 he left no heirs.
His 1597 will bequeathed his territory between his nephew, Maurice of Hesse-Kassel and Louis V of Hesse-Darmstadt, on the condition that it would remain Lutheran.
Moritz, Landgrave of Hesse
Moritz, Prince and Landgrave of Hesse(" Moritz Friedrich Karl Emanuel Humbert" 6 August 1926 – 23 May 2013) was the son of Prince Philip, Landgrave of Hesse, and the head of the House of Brabant and the German House of Hesse.
George II, Landgrave of Hesse-Darmstadt
George II of Hesse- Darmstadt,( 17 March 1605, in Darmstadt – 11 June 1661) was the Landgrave of Hesse- Darmstadt from 1626 to 1661.
He was the son of Ludwig V and Magdalene of Brandenburg.
He married Sophia Eleonore of Saxony on 1 April 1627.
From 1645 to 1648 he led the so- called" Hessenkrieg" against the Landgravine Amalie Elizabeth of Hesse- Kassel over the inheritance of the extinct line of Hesse- Marburg.
This conflict resulted in the loss of Hesse- Marburg to Hesse- Kassel.
Hermann II, Landgrave of Thuringia
Hermann II( 28 March 1222 in Creuzburg – 3 January 1241) was the Landgrave of Thuringia and the son of Louis IV, Landgrave of Thuringia, and Saint Elizabeth of Hungary.
Gustav, Landgrave of Hesse-Homburg
Gustav, Landgrave of Hesse- Homburg( 17 February 1781 – 8 September 1848) was landgrave of the German state of Hesse- Homburg from 1846 to 1848.
Christine of Saxony
Christine of Saxony (25 December 1505 – 15 April 1549) was a German noble, landgravine of Hesse.
She was the regent of Hesse in 1547-1549.
She was the daughter of George the Bearded, Duke of Saxony and Barbara Jagiellon.
On 11 December 1523 in Kassel, she married Landgrave Philip I, Landgrave of Hesse.
The marriage was arranged to forge an alliance between Hesse and Saxony and was unhappy; Philip claimed to be disgusted by her and only shared her bed by duty.
They had ten children.
Whilst married to Christine, Philip practised bigamy and had another nine children with his other (morganatic) wife, Margarethe von der Saale; in 1540, Christine gave her consent to her husband's bigamy with his lover because of her view upon him as her sovereign.
Margarethe von der Saale, however, was never seen at court.
During Philip's absence and captivity in 1547-49, Christine was regent jointly with her oldest son.
Ernest Constantine, Landgrave of Hesse-Philippsthal
Ernest Constantine, Landgrave of Hesse-Philippsthal (8 August 1771 in Philippsthal – 25 December 1849 in Meiningen) was a member of the House of Hesse and Landgrave of Hesse-Philippsthal from 1816 until his death.

Question: Who is Louis Iv, Landgrave Of Hesse-Marburg's maternal grandmother?
Answer: Barbara Jagiellon