Thadeus von Sivers

Thadeus Ferdinand Ludwig Freiherr von Sivers (Фадде́й Васи́льевич Си́верс, tr. Faddey Vasil'evich Sivers; 16 October 1853 – ?), always known by the false name Thadeus von Sievers, was a Baltic German general who served in the Imperial Russian Army. Sievers was most notable for his role in the Invasion of East Prussia during the initial stage of World War I, in which he commanded the 10th Army against the Germans with numerous successes.