Christian, Duke of Saxe-Weissenfels
Christian, Duke of Saxe- Weissenfels( 23 February 1682 in Weissenfels – 28 June 1736 in Sangerhausen), was a duke of Saxe- Weissenfels- Querfurt and member of the House of Wettin.
He was the sixth( but second surviving) son of Johann Adolf I, Duke of Saxe- Weissenfels, and Johanna Magdalena of Saxe- Altenburg.
John George I, Duke of Saxe-Eisenach
Johann Georg I, Duke of Saxe- Eisenach( Weimar, 12 July 1634 – hunting accident, Eckhartshausen, Marksuhl, 19 September 1686).
He was the fifth but third surviving son of Wilhelm, Duke of Saxe- Weimar and Eleonore Dorothea of Anhalt- Dessau.
After the death of his father( 1662), his older brother Johann Ernst II inherited Weimar, and his second brother Adolf Wilhelm received Eisenach.
Johann Georg received an income from the new duchy of Saxe- Eisenach and took his residence in the small town of Marksuhl.
In 1668 his brother Adolf Wilhelm died.
His fifth and only surviving son, Wilhelm August, was born eight days after his father's death and became duke from the moment of his birth; Johann George became the regent of the duchy and also the guardian of the new duke.
Wilhelm August died in 1671 at only two years of age, and Johann Georg inherited the duchy.
The next year( 1672) the death without heirs of the Duke Frederick Wilhelm III of Saxe- Altenburg forced a new treaty of division of the family lands between Johann Georg, his surviving brothers and his cousin.
Johann Georg was confirmed in his possession of Eisenach and took some towns, and his younger brother, Bernhard, inherited Jena.
Johann Georg thus became the founder of the most recent line of the dukes of Saxe- Eisenach, who became extinct in 1741.
He was ruler in 1685 when Johann Sebastian Bach was born in the duchy.
Frederick, Duke of Saxe-Weissenfels-Dahme
Frederick of Saxe- Weissenfels(" Frederick Erdmann"; b. Halle, 20 November
1673- d. Dahme, 16 April 1715), was a German prince member of the House of Wettin and Duke of Saxe- Weissenfels- Dahme.
He was the sixth son of Augustus, Duke of Saxe- Weissenfels but first- born from his second marriage with Johanna Walpurgis of Leiningen- Westerburg.
Johann Adolf I, Duke of Saxe-Weissenfels
Johann Adolf I, Duke of Saxe- Weissenfels( 2 November 1649, in Halle – 24 May 1697, in Weissenfels), was a duke of Saxe- Weissenfels- Querfurt and member of the House of Wettin.
He was the first son of Augustus, Duke of Saxe-Weissenfels, and his first wife, Anna Maria of Mecklenburg- Schwerin.
August of Saxe-Weissenfels (1650–1674)
August of Saxe-Weissenfels (3 December 1650 in Halle – 11 August 1674 in Halle), was a member of the Albertine branch of the House of Wettin.
He was a titular Duke of Saxe-Weissenfels and a Provost of Magdeburg.
He is sometimes called "August the Younger", to distinguish him from his father.
Albrecht of Saxe-Weissenfels
Albrecht of Saxe- Weissenfels( 14 April 1659 in Halle – 9 May 1692 in Leipzig), was a German prince of the House of Wettin.
He was the fifth and youngest son of August, Duke of Saxe- Weissenfels, and his first wife, Anna Maria of Mecklenburg- Schwerin.
John George II, Duke of Saxe-Eisenach
Johann Georg II, Duke of Saxe- Eisenach( Friedewald, 24 July
1665 – Eisenach, 10 November 1698), was a duke of Saxe- Eisenach.
He was the second son of Johann Georg I, Duke of Saxe- Eisenach and Johannetta of Sayn- Wittgenstein.
The death of his older brother, Frederick August—who was killed in battle in 1684 — make him the new heir of the duchy of Saxe- Eisenach.
Two years later( 1686), Johann Georg succeeded his father when he died.
In Kirchheim unter Teck on 20 September 1688 Johann Georg married with Sophie Charlotte of Württemberg.
This union was childless.
When his cousin, the young Duke Johann Wilhelm of Saxe- Jena died( 1690) Johann Georg inherited a part of his duchy, because he was compelled to make a divisionary treaty with the Duke Wilhelm Ernst of Saxe- Weimar, his other cousin and brother- in- law of the late duke.
Johann Georg died suddenly of smallpox, and was succeeded by his brother, Johann Wilhelm.
Johanna Magdalene of Saxe-Weissenfels
Johanna Magdalene of Saxe- Weissenfels( 17 March 1708 – 25 January 1760), was a Duchess consort of Courland.
She married the Duke of Courland, Ferdinand Kettler, on 20 September 1730.
She was the daughter of Johann Georg, Duke of Saxe- Weissenfels and Fredericka Elisabeth of Saxe- Eisenach.
The marriage was childless.
Johann Adolf II, Duke of Saxe-Weissenfels
Johann Adolf II, Duke of Saxe- Weissenfels
( Weissenfels, 4 September 1685 – Leipzig, 16 May 1746), was the last duke of Saxe- Weissenfels- Querfurt and a member of the House of Wettin.
He was also a commander in the Saxon army.
Johann Adolf was the youngest of the eleven children of Johann Adolf I, Duke of Saxe- Weissenfels, and Johanna Magdalena of Saxe- Altenburg.
His mother died five months after his birth, on 22 January 1686.
Johann Georg, Duke of Saxe-Weissenfels
Johann Georg, Duke of Saxe- Weissenfels( 13 July 1677, in Halle – 16 March 1712, in Weissenfels), was a duke of Saxe- Weissenfels- Querfurt and a member of the House of Wettin.
He was the third child and first surviving son of Johann Adolf I, Duke of Saxe-Weissenfels, by his first wife, Johanna Magdalena of Saxe- Altenburg.

Question: Who is the paternal grandfather of Johann Georg, Duke Of Saxe-Weissenfels?