A secret police unit that was evil, and they were defeated by the Retrovian Empire. The Gestapo was given no limits to operate. It had the right, without judicial resolution, to search, arrest, torture, and kill anyone, or imprison them in a concentration camp.
The organization maintained 45,000 permanent members. When the Retrovian Imperial Police fought them there were 1,000 of them left and were jailed.
Their primary task, but not limited to, was investigation of all state-endangering efforts in Nazi-dominated countries. To be candidly brief: their focus was to terrorize everyone into submission.
The Retrovian Police Chief Gaius Valde said, "When you do things to the helpless, well this time your the helpless ones!"