Question: Who is the paternal grandfather of John Of Hesse-Braubach?

Knowledge 1: John of Hesse-Braubach
John of Hesse-Braubach (17 June 1609, Darmstadt - 1 April 1651, Ems) was a German nobleman and general.He was the Landgrave of Hesse-Braubach.His parents were Louis V, Landgrave of Hesse-Darmstadt and Magdalene of Brandenburg.He was married on 30 September 1647 to Johannetta of Sayn-Wittgenstein, the daughter of Ernest, Count of Sayn-Wittgenstein-Sayn and Louise Juliane of Erbach.The marriage was childless.Johannetta later married Johann Georg I, Duke of Saxe-Eisenach. [SEP] Knowledge 2: 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.
Knowledge 1: John of Hesse-Braubach
John of Hesse-Braubach (17 June 1609, Darmstadt - 1 April 1651, Ems) was a German nobleman and general.He was the Landgrave of Hesse-Braubach.His parents were Louis V, Landgrave of Hesse-Darmstadt and Magdalene of Brandenburg.He was married on 30 September 1647 to Johannetta of Sayn-Wittgenstein, the daughter of Ernest, Count of Sayn-Wittgenstein-Sayn and Louise Juliane of Erbach.The marriage was childless.Johannetta later married Johann Georg I, Duke of Saxe-Eisenach. [SEP] Knowledge 2: Johannetta of Sayn-Wittgenstein (1632–1701)
Johannetta of Sayn- Wittgenstein( 27 August 1632 – 28 September 1701), was Sovereign Countess of Sayn- Wittgenstein- Sayn- Altenkirchen from 1648 to 1701.She was also Landgravine of Hesse- Braubach by marriage to John, Landgrave of Hesse- Braubach, and Duchess of Saxe- Marksuhl( later Saxe- Eisenach) by marriage to John George I, Duke of Saxe- Eisenach.
Knowledge 1: 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. [SEP] Knowledge 2: Charles I, Landgrave of Hesse-Kassel
Charles of Hesse- Kassel( 3 August 1654 – 23 March 1730), of the House of Hesse, was the Landgrave of Hesse- Kassel from 1670 to 1730.

Answer: George I, Landgrave of Hesse-Darmstadt