Philipp von Boeselager was one of eight officers who planned to shoot Hitler and SS head Heinrich Himmler in March 1943 on a visit to the eastern front, but the plot was called off after Himmler decided not to come.
Von Boeselager was also one of 200 men and women involved in a July 1944 assassination attempt when a bomb was planted under a table in Hitler's eastern headquarters in East Prussia.
The bomb exploded, but the Nazi leader escaped with slight injuries because an officer had moved the briefcase containing the explosives behind a sturdy leg of the oak table.
Claus Schenk von Stauffenberg and other officers involved in the plot were rounded up and executed the same day, but von Boeselager, who had obtained the explosives, escaped detection.
The episode is currently being turned into a Hollywood movie with Tom Cruise playing von Stauffenberg.
Von Boeselager was the last surviving member of the group. He died overnight on Thursday.