Der Hintergedanke was a cult formed by the Sith Lord Darth Verraeter after he left the Jedi during the Darkness era. It was founded in 1,113 ABY. The cult's main army consisted of the Mandalorians and the Hintergedanke Crusaders. The cult became an official religion following the Der Hintergedanke vs. Jedi Order court case.
Behind the scenes[]
Der Hintergedanke is German for "hidden agenda," or, literally, "the idea behind." It can also mean "ulterior motive."