First Battle of the Masurian Lakes
Paul von Hindenburg, general of the German Eighth Army, knew the swampy area of East Prussia called the Masurian Lakes. He thought the Russians might attack there so he made plans in case of such an attack. At this time of the war, the Germans knew what the Russians were planning because they could read their messages. The Russians planned their attack on East Prussia with little intelligence of the area. They had no rail transport to move troops. They failed to plan for enough food and ammunition and moved only with horses and infantry. But they had superior numbers and were confident they could defeat the Germans.