After the end of World War II the Soviet occupying forces instituted a land reform, confiscating land held by nobility. The Hagen family lost the Möckern castle and a branch of the State Archives Magdeburg was installed there.
After WWII, Soviet forces carried out a land reform, seizing property from the nobility. The Hagen family lost Möckern castle, and part of the Magdeburg State Archives was relocated there.