Magdalene Sibylle of Prussia was an Electress of Saxony as the spouse of John George I, Elector of Saxony.
Background
She was born in Königsberg, the daughter of Albert Frederick, Duke of Prussia and Marie Eleonore of Cleves. She was a great granddaughter of Ferdinand I, Holy Roman Emperor.
Career
She is also three times ancestor of Augusta of Saxe-Gotha, mother of George III of the United Kingdom. In that way, she connected the ancestry of the British monarchs to the Catholic Monarchs. She used Swedish prisoners of war to work on the Dresdner Festungsbau ("Dresden fortress").
As a widow in 1656, she retired to the Dresdner Frau Kurfürstin-Haus and died in Dresden in 1659.