Kurt Freiherr von Plettenberg (1891-1945) was the descendant of Westphalian aristocratic family, and a soldier in both world wars. The expectations, which he along with many of his later fellow conspirators of the 20 July 1944 plot to kill Hitler initially had of the Third Reich, are soon disappointed, when he recognises the true nature of the regime. When he accepts the office as general agent of the former Prussian royal house of the Hohenzollerns in 1942, he already belongs to the inner circle of the resistance planning Operation Valkyrie.After the assassination attempt, however, he is not immediately discovered as one of the conspirators. Out of consideration for the house of Hohenzollern, which Hitler considers to be his most dangerous internal enemy, he acted more carefully than many others. Yet only a few weeks before the end of the war Plettenberg is finally denounced and arrested, too.This biography shows for the first time how Kurt von Plettenberg, who belonged to the inner circle of conspirators around Stauffenberg, found a way to prevail during those difficult times and how significantly he influenced the resistance.