During the revolt — known as the Maji Maji Rebellion — between 200,000 and 300,000 Indigenous people were murdered, as German troops systematically wiped out villages and fields, experts say.
Germany’s long-standing commitment to historical remembrance has centred around the atrocities it committed during World War II, specifically the slaughter of six million Jews and other minorities during the Holocaust.
While I had heard about the genocide in Namibia, I don’t think my history lessons (which mainly center around WWII and the surroundings, including the holocaust) ever mentioned such a slaughter in Tanzania. (edit: They were also 20 years ago, if you are German and younger, feel free to tell me if anything changed)
Wikipedia (German links are far more detailed if you speak it):