Background
He was the second son of John William, Duke of Saxe-Weimar and Dorothea Susanne of Simmern. His father died in 1573, when John was only three years old.
He was the second son of John William, Duke of Saxe-Weimar and Dorothea Susanne of Simmern. His father died in 1573, when John was only three years old.
But when they demanded their own inheritance in 1603, he resisted their demands. This line of Saxe-Altenburg became extinct in 1672, and all the inheritance passed to the line of Saxe-Weimar, John"s descendants. In Altenburg on 7 January 1593, John married Dorothea Maria of Anhalt (b 2 July 1574 d 18 July 1617).
They had twelve children:
John Ernest I, Duke of Saxe-Weimar (b Altenburg, 21 February 1594 – d Sankt Martin, Hungary, 6 December 1626).
Christian William (b and d Altenburg, 6 April 1595). Frederick (b Altenburg, 1 March 1596 – killed in battle, Fleurus, Belgium, 19 August 1622).
John (b Weimar, 31 March 1597 – d Weimar, 6 October 1604). William, Duke of Saxe-Weimar (b Altenburg, 11 April 1598 – d Weimar, 17 May 1662). stillborn son (Altenburg, 11 April 1598), twin of William.
Albert IV, Duke of Saxe-Eisenach (b Altenburg, 27 July 1599 – d Eisenach, 20 December 1644).
John Frederick (b Altenburg, 19 September 1600 – d Weimar, 17 October 1628). Ernest I, Duke of Saxe-Gotha (b Altenburg, 25 December 1601 – d Schloss Friedenstein, Gotha, 26 March 1675). Frederick William (b Weimar, 7 February 1603 – d Georgenthal, 16 August 1619).
Bernhard (b Weimar, 6 August 1604 – d Neuenburg, 18 July 1639), Count of Franken (1633).
Johanna (b posthumously, Weimar, 14 April 1606 – d Weimar, 3 July 1609).