Duchess Anna of Prussia and Jülich-Cleves-Berg was the daughter of Albert Frederick, Duke of Prussia, and Marie Eleonore of Cleves.
Background
Before the marriage, his mother, Catherine of Brandenburg-Küstrin, pointed out that Anna was not beautiful, but the marriage was arranged in order to secure the incorporation of the Duchy of Prussia into the Electorate of Brandenburg through Anna, whose father had no surviving male heirs.
Career
She became the spouse of John Sigismund, Elector of Brandenburg. Anna was married to John Sigismund on 30 October 1594. This was a political match of exceptional importance, since Anna was not only heir to Prussia, but also the expected heir of Cleves, Jülich and Berg, as well as Mark and Ravensberg.
Anna was described as intellectually superior to her spouse, temperamental and strong-willed.
She is reported to have thrown plates and glasses at her spouse during arguments. She fought on her own to secure her succession rights to various fiefs and handled negotiations with her competitors.
In 1612, she placed her demands before the Emperor. George William (13 November 1595 – 1 December 1640).
Successor of John Sigismund.
Anne Sophia of Brandenburg (15 March 1598 – 19 December 1659). Married Frederick Ulrich, Duke of Brunswick-Lüneburg. Maria Eleonora of Brandenburg (11 November 1599 – 28 March 1655).
Married Gustavus Adolphus of Sweden.
Catherine of Brandenburg (28 May 1602 – 27 August 1644). Married first Gabriel Bethlen, Prince of Transylvania and secondly Franz Karl of Saxe-Lauenburg.
Joachim Sigismund of Brandenburg (25 July 1603 – 22 February 1625). Agnes of Brandenburg (31 August 1606 – 12 March 1607).
John Frederick of Brandenburg (18 August 1607 – 1 March 1608).
Albrecht Christian of Brandenburg (7–14 March 1609).