"Duchess Sophie of Prussia (c. 31 March 1582 – c. 24 November 1610) was a German princess of the Duchy of Prussia, a fief of Kingdom of Poland and a member of the House of Hohenzollern.
Sophie was the daughter of Albert Frederick, Duke of Prussia, and Marie Eleonore of Cleves. She was courted by Wilhelm Kettler, son of Gotthard Kettler of Courland and Anna of Mecklenburg-Schwerin. Their marriage contract was signed in Königsberg on 5 January 1609. Sophie died on 24 November 1610, four weeks after the birth of her only son, Jacob, who later succeeded his paternal uncle Friedrich Kettler as Duke of Courland." - (en.wikipedia.org 01.06.2020)
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