"Sibylle of Jülich-Cleves-Berg, Margravine of Burgau (26 August 1557 in Cleves – 1628 in Günzburg) was the daughter of Duke William the Rich and his second wife, Archduchess Maria of Austria.
Her brother John William inherited the United Duchies of Jülich-Cleves-Berg in 1592. After he had developed a mental illness, a power struggle broke out at court between Sibylle and her sister-in-law Jakobea of Baden. Sibylle won, and imprisoned Jakobea. Sibylle may also have been partially responsible for Jakobea´s violent death in 1597.
In 1601, Sibylle married Margrave Charles of Burgau. In 1610, the couple moved into the residence at Günzburg. Here, she entertained a feudal court, even after her husband died in 1618. She acted in particular as patron of music." - (en.wikipedia.org 02.10.2020)