Sidonie of Saxony was born on 8 March 1518 as the daughter of Henry IV, Duke of Saxony and his wife, Catherine of Mecklenburg. Sidonie was their third daughter, and she had a total of five siblings.
On 17 May 1545, Sidonie married Eric II, Duke of Brunswick-Lüneburg, who was ten years younger than she was. The wedding was held in Hannoversch Münden, apparently without much pomp. He had broken off his previous engagement to Agnes of Hesse in order to marry Sidonie. Agnes went on to marry Sidonie’s brother Maurice, and she became the mother of Anna of Saxony.
The marriage of Sidonie and Eric started off well enough, but as he succeeded his father as Duke in 1547, the problems began. Eric reconverted to the Catholic faith, while Sidonie held on to her Lutheran faith. The added problem of their childlessness caused friction between them. In 1555, rumours began to circulate that Eric wanted to poison Sidonie. He also took a mistress whom he housed at Calenberg Castle and had two children with. Sidonie was denied access to Calenberg Castle after she threatened to cut off “the whore’s nose and poke out an eye.”
The situation was to become even worse. From 1564, she was practically under house arrest, and when Eric fell ill, she was accused of witchcraft. Four women were burned as witches and Eric used information retrieved from them under torture as evidence against Sidonie. On 17 December 1573, the case was presented to the court, but Sidonie was cleared of all charges just one month later. Sidonie managed to travel to Vienna and then onto Dresden, where her brother and his wife lived. Eventually, she managed to get a settlement and pension for life. Her youngest brother Augustus, who succeeded Maurice as Elector of Saxony in 1553, gave her the Poor Clares monastery at Weißenfels for its income. She lived there for the last few years of her life. She died on 4 January 1575 and was buried in Freiberg Cathedral.
Her fighting spirit shines through in a letter she wrote in 1573 about her husband, which reads (partly):
Duke Eric is difficult because he spewed out accusations, taking, as we speak, not the clothes, but the honour, which is the highest and most precious treasure a poor woman in this world possesses. 1