Willisen was born in
Bärenwalde,
West Prussia,
German Empire (modern Bincze, Poland), he served in the
German Army in
World War I. In 1923 Willisen graduated in forestry and worked in the public forest service. Willisen became an opponent of the Nazi regime after his uncle
Herbert von Bose was murdered in the
Night of the Long Knives in 1934.{{cite book|url=http://library.fes.de/pdf-files/bueros/schwerin/05669.pdf Willisen was designated as a political commissioner in
military district II (
Stettin) after a successful coup against Hitler. Willisen was arrested on 21 July 1944 after the plot had failed but was released from custody some weeks later because the
Gestapo was unable to prove his knowledge about his future role in the plotter's plans. Willisen returned to Schwerin and survived the war. After World War II Willisen led the forestry office of
Reinhausen near
Göttingen. He retired in 1964 and died in 1983 in Munich. ==Notes==