Francis I ( Francis Stephen ; 8 December 1708 â `` 18 August 1765 ) was Holy Roman Emperor and Grand Duke of Tuscany , though his wife effectively executed the real power of those positions .
Francis I ( Francis Stephen ; 8 December 1708 -- 18 August 1765 ) was Holy Roman Emperor and Grand Duke of Tuscany , though his wife effectively executed the real power of those positions .