In which country did Anton Ludwig August von Mackensen lead an Army Group from 1916-1918?
Army Group Mackensen (Romania): The Army Group Mackensen (German: "Heeresgruppe Mackensen") which operated against Romania between 28 August 1916 and 7 May 1918 during World War I under the command of Field Marshal Mackensen, was an Army Group of the German Army. August von Mackensen: Anton Ludwig August von Mackensen (6 December 1849 – 8 November 1945), born August Mackensen, was a German field marshal.
Romania