You probably never heard of him - I hadn't until some days ago -, but Philipp von Boeselager was the last surviving member of the group that plotted "operation Valkyrie", the failed conspiracy to kill Hitler on 20 July, 1944. He died in his sleep, at age 91, on May 1.
He survived because none of his co-conspirators, even under torture, gave away his name. He was the man who procured and prepared the explosives and fuses for the bomb that went off in the Führerhauptquartier.
He led a quiet life after the war; in later years, he talked to school classes and students about the plot; for all those years, he was obsessed about the fact that on one occasion, he was 60 cm away from Hitler with a loaded gun in his pocket, but didn't shoot. This was an earlier attempt to kill Hitler during a meeting, but the group leader had forbidden the killing when he had heard that Hitler would be at the meeting without Himmler, the chief of the SS; he feared civil war would ensue should Hitler be killed but Himmler left alive.
To its eternal shame, Germany's modern army, the Bundeswehr, never once invited him to speak before its officers, never gave him any honours for his courage, and never named anything after him or some such. The Bundeswehr was built using old Wehrmacht and Nazi personnel, and those firmly injected into the self image of the new army that it wouldn't honour "traitors" who had "reneged" on their oath of service (which at the time was a personal oath to Hitler). Times have improved since, but not quick enough to give von Boeselager his due.