Who is Erhardt von Thadden from A Thread of Grace and what is their importance?

As Gruppenfuhrer, or division commander, von Thadden is known as the schoolteacher due to his long academic ramblings. He thinks he is quite clever and sees the war as a giant chess game. Arrogant and impressed with his own status in the military, he lives in luxury and has a sneering, sarcastic personality. Von Thadden eventually decides to make a road trip into the mountains without a military escort and is kidnapped by partisan soldiers and held as a hostage. He meets his death when the partisans hold a mock trial, showing the citizens photos of atrocities and allowing them to take out their rage on von Thadden and the other hostages.