"Frederick William, Duke of Brunswick-Wolfenbüttel (German: Friedrich Wilhelm; 9 October 1771 – 16 June 1815) was a German prince and Duke of Brunswick-Lüneburg and Oels. Nicknamed "The Black Duke", he was a military officer who led the Black Brunswickers against French domination in Germany. He briefly ruled the state of Brunswick-Wolfenbüttel from 1806 to 1807 and again from 1813 to 1815." - (en.wikipedia.org 31.01.2020)
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