He served with distinction in the Seven Years ' War .
The son of a noble family of Hesse - Kassel ( or Hesse - Cassel ) , Donop was well connected in the European courts and served as personal adjutant to the Landgrave of Hesse - Kassel .
son served with distinction in the Seven Years ' War .
The son of a noble family of Hesse - Kassel ( or Hesse - Cassel ) , Donop was well connected in the European courts and served as personal adjutant to the Landgrave of Hesse - Kassel .