Charles William Ferdinand, Duke of Brunswick references on wikipedia
Charles_William_Ferdinand,_Duke_of_Brunswick Charles II William Ferdinand, Duke of Brunswick-Wolfenbuettel (Karl II. Wilhelm Ferdinand, Herzog von Braunschweig-Wolfenbüttel) (October 9, 1735 - October 16 1806) was a sovereign prince of the Holy Roman Empire, and a professional soldier who served as a Generalfeldmarschall of the Kingdom of Prussia.