About Margravine Elisabeth Sophie of Brandenburg (1674–1748)
Elisabeth Sophie of Brandenburg (5 April 1674 – 22 November 1748), was a Duchess consort of Courland by marriage to Duke Frederick Casimir Kettler of Courland, a Margravine consort of Brandenburg-Bayreuth by marriage to Christian Ernst, Margrave of Brandenburg-Bayreuth, and a Duchess consort of Saxe-Meiningen by marriage to Ernst Ludwig I, Duke of Saxe-Meiningen.
She was joint regent in Courland during the minority of her son Frederick William, Duke of Courland from 1698 until 1701.
Source: Scan aus aus dem Buch: Hans-Otto Keunecke (Hrsg.): Das Erlanger Schloss als Witwensitz 1712 – 1817. Universitätsbibliothek Erlangen-Nürnberg 2002. ISBN 3-930357-52-6 License: CC-PD-Mark PD-Art (PD-old-100)