About Frederick William, Duke of Brunswick-Wolfenbüttel
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.