Sophia Eleonore of Hesse-Darmstadt
Sophia Eleonore of Hesse- Darmstadt( 7 January 1634 in Darmstadt – 7 October 1663 in Bingenheim, now part of Echzell), was Landgravine of Hesse- Darmstadt by birth and by marriage Landgravine of Hesse- Homburg.
She was a daughter of Landgrave George II of Hesse- Darmstadt( 1605 – 1661) from his marriage to Sophia Eleonore( 1609 – 1671), the daughter of Elector John George I of Saxony.
Prince Francis Ernest of Hesse-Darmstadt
Francis Ernest of Hesse- Darmstadt( born 25 January 1695 in Gießen; died: 8 January 1716 in Darmstadt) was a German nobleman.
He was the third son of Count Landgrave Ernest Louis of Hesse- Darmstadt( 1667 – 1739) from his marriage to Dorothea Charlotte( 1661 – 1705), daughter of the Margrave Albert of Brandenburg- Ansbach.
He replaced his brother Charles William of Hesse- Darmstadt as Colonel of the Hesse- Darmstadt Kreis Regiment when Charles William died during the War of Spanish Succession.
Philip of Hesse-Darmstadt
Philip of Hesse- Darmstadt( July 20, 1671 in Darmstadt – August 11, 1736 in Vienna) was a Prince of Hesse- Darmstadt, Imperial Field marshal and Governor of Mantua.
Louis VI, Landgrave of Hesse-Darmstadt
Louis VI of Hesse-Darmstadt  (25 January 1630 – 24 April 1678) was Landgrave of Hesse-Darmstadt from 1661 to 1678.
He was the eldest of three sons of the Landgrave George II of Hesse-Darmstadt and Sophia Eleonore of Saxony.
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.
Juliana of Hesse-Darmstadt
Juliana of Hesse-Darmstadt (14 April 1606 in Darmstadt – 15 January 1659 in Osterode am Harz) was the wife of Count Ulrich II of East Frisia and was regent for her minor son Enno Louis from 1648 to 1651.
Her parents were Landgrave Louis V of Hesse-Darmstadt and Magdalene of Brandenburg, daughter of Elector John George von Brandenburg.
Juliana arrived in East Frisia on 5 March 1631 and married count Ulrich II on the same day.
She and her husband had three sons: Enno Louis, George Christian and Edzard Ferdinand.
Even during the turmoil of the Thirty Years' War Ulrich managed to build a Lustschloss for his wife at Sandhorst.
It was completed in 1648 even though East Frisia had to endure great hardship during the war, due to various foreign occupiers.
After her husband's death, she was appointed guardian of her minor sons, and regent of the county.
However, she sent her cumbersome sons abroad and lived a life of decadence, leaving the management of the badly damaged county in the hands of her favourites, who managed the county poorly.
This led to increasing problems with the East Frisian Estates.
Most notable among these favourites were Secret Councillor Johann von Marenholz and his wife Elisabeth von Ungnad zu Sonneck, who a been a lady-in-waiting for Juliana.
Juliana was alleged to have had an affair with Marenholz, which later proved his undoing.
He was executed in Wittmund on 21 July 1651, after a show trial.
In the meantime, Juliana had moved the court from Aurich to Sandhorst to be able to indulge in the sweet life undisturbedly.
Many East Frisians held that under Marenholz and his wife, the problems of the county had gotten out of hand and urged the young Count Enno Louis to return to his County.
Emperor Ferdinand III declared Enno Louis to be an adult in 1651 and in May that year Enno Louis removed his mother from government.
She was sent to her Wittum at Berum Castle.
In 1654 she bought the farm Westerhof in Osterode am Harz, where she died on 15 January 1659.
Magdalene of Brandenburg
Magdalene of Brandenburg, also Magdalene and Magdalen, (7 January 1582 – 4 May 1616) was the daughter of John George, Elector of Brandenburg and his third wife Elisabeth of Anhalt-Zerbst.
She married Louis V, Landgrave of Hesse-Darmstadt.
Prince George Charles of Hesse-Darmstadt
George Charles( German:" Georg Karl") of Hesse- Darmstadt( 14 June 1754- 28 January 1830, Schüttrisberg, now in Slovakia) was a German prince of the House of Hesse- Darmstadt.
He was the fourth child and third son of Prince George William of Hesse- Darmstadt and Countess Maria Louise Albertine of Leiningen- Dagsburg- Falkenburg.
Prince Charles William of Hesse-Darmstadt
Karl Wilhelm of Hesse- Darmstadt( 17 June 1693, Nidda- 17 May 1707, Gießen) was a Prince of Hesse- Darmstadt.
Marie Hedwig of Hesse-Darmstadt
Marie Hedwig of Hesse- Darmstadt( 26 November 1647 in Giessen – 19 April 1680 in Ichtershausen) was a landgravine of Hesse- Darmstadt by birth and by marriage Duchess of Saxe- Meiningen.

Question: Who is Juliana Of Hesse-Darmstadt's maternal grandfather?
Answer: John George, Elector of Brandenburg