Carl-Hans Graf von Hardenberg entered the German army. In 1914 he married Countess Renate von der Schulenburg (1888-1959). He was wounded several times during World War I. In 1921, having reached the rank of major, he gave up his military commission and settled at his castle in Neuhardenberg. Besides his farming, he was active in communal politics, engaged in administration of the district of Lebus in the province of Brandenburg, and was active in the Protestant noblemen's Order of Saint John.Robert M. Clark, Jr., The Evangelical Knights of Saint John; Dallas, Texas: 2003; p. 46. Von Hardenberg was admitted to the Order as a Knight of Honor in 1922, promoted to Knight of Justice in 1929, and in 1948 became Commander of the Commandery of Brandenburg. When the National Socialist Party came to power in 1933, Hardenberg refused to join any of the party-sponsored organizations and was removed from all his positions.
