Military theorist, "On War" author.

Carl Philipp Gottfried (or Gottlieb) von Clausewitz (1 July 1780 – 16 November 1831) was a Prussian general and military theorist who stressed the "moral" (in modern terms meaning psychological) and political aspects of waging war.

(Fall Clausewitz) the code word initiating the defence of Berlin by Nazi Germany during the final stage of the European Theatre of World War II.