Johann Adolf I, Duke of Saxe-Weissenfels

[1] At his estate, near the Guardhouses (Kavaliershaeuser), Johann Adolf created the most important formal garden in central Germany of his time.

When the county of Rosenburg fell to the Archbishopric of Magdeburg in 1659 after the extinction of the male line of the counts of Barby, Johann Adolf's father, duke August, continued to administer these areas (which were not a part of this patrimony) in spite of the protests of the Electors of Brandenburg and Saxony, who desired those lands in accordance with the terms of the Peace of Westphalia.

In 1666, the Elector of Saxony finally consented to give Barby and Rosenberg to duke August until the extinction of the Weissenfels line.

After his father's death, Johann Adolf turned to the elector of Brandenburg to obtain a declaration of nullity for the sales contract that relinquished Rosenberg.

Due to the debts accumulated by his father, Johann Adolf was forced in 1687 to sell Burg bei Magdeburg.

They had eleven children: After the death of his wife in 1686, Johann Adolf married a second time in Querfurt on 3 February 1692 to Christiane Wilhelmine of Bünau.