What is the name of the small village in northeastern Poland that was the scene of a major Russian defeat by German forces during World War 1?

Tannenberg. The actual defeat of the Russians was spread over a large area and the battle was only called after this place because the Poles had defeated the Teutonic Knights at Tannenberg in 1410. Tannenbaum. This is a widely studied battle in which a small part of the German army defeated a much larger Russian force, thus protecting Germany's eastern frontier from a Russian invasion. The bulk of the German army (about 85%) was fighting in France at the time. The German plan was to send most of its army into France and quickly defeat the French army, then race east to defeat the slower-mobilizing Russians. If not for the victory at Tannenbaum, the Germans might have had to pull armies out of France to prevent a Russian invasion into Germany.