Johannes Friedrich "Hans" von Seeckt (22 April 1866 – 27 December 1936) was a German military officer who served as Chief of Staff to August von Mackensen, and was a central figure in planning the victories Mackensen achieved for Germany in the east. In the interwar years he laid out the organization of the Reichswehr, the small army the Weimar Republic was allowed to have following the armistice. He served as a member of parliament from 1930 to 1932, and from 1933 to 1935 was repeatedly in China as a military consultant to Chiang Kai-shek in his war against the Communists.