Anna left Stegeborg to attend the death bed of queen dowager Gunilla Bielke in 1597, Duke Charles had her household searched, the box of Ebba Sparre and the correspondence between Anna and the Sparre couple confiscated, and subjected Ebba Sparre as well as her sister Anna's senior lady in waiting Margareta Brahe to an interrogation regarding the Cryptography he found in Anna's papers, and accused Ebba Sparre of having smuggled in her brother, Anna's alleged lover Gustav Brahe to her. From 1592, Sigismund negotiated a marriage between Anna and Margrave John George of Brandenburg but political tensions kept delaying the agreement. In February 1598, Sigismund demanded that Charles allow Anna to return to Poland as her wedding to John George was finally set to Easter that year. Charles attempted to prevent her departure by demanding an inventory of her Swedish property and the promise that it would be confiscated by the state should she die unmarried. Anna protested, advised Charles to cooperate with Sigismund and offered herself as a mediator. At the return of Sigismund to Sweden, Anna immediately joined him in the civil war that erupted between Sigismund and Charles. She was given the task to mediate, but because of Charles' lack of confidence in her, she was not able to achieve much. After Sigismund's defeat at the Battle of Stångebro in 1598, she left Sweden to live with him in Poland. Later life in Poland After 1598, Anna spent the rest of her life in Poland, though she always referred to herself as a Princess of Sweden. Known as Anna of Svecia (Anna of Sweden), she was a Protestant member of a Catholic royal family, and acted as a protector of the exiled Protestant Swedish loyalists of Sigismund and Polish Protestants. Princess Anna maintained a good relationship with and influence upon Sigismund, and she functioned as his political adviser on the affairs of state, something which made her a controversial figure in Poland. During the captivity of Carl Gyllenhielm, an illegitimate son of Duke Charles, in Poland in 1610–13, she gave him much attention. She was given the task of interrogating Gyllenhielm by Sigismund, who listened hidden by a curtain. She accused Charles of conspiracy to entice conflict between Sigismund and John III, something Gyllenhielm denied. Anna remained unmarried. In 1602, duke Charles de Gonzaga-Nevers suggested a marriage to a French prince, which was never realized. The negotiations