The Second Battle of the Masurian Lakes is also known as the Winter Battle of the Masurian Lakes because it began during a severe blizzard. German General Paul von Hindenburg had a plan for a decisive push against Russia to bring an end to the war on the Eastern Front. General Hindenburg wanted to push the Russians back beyond the Vistula River. Hindenburg planned to have the Eighth, led by General Otto von Below, and Tenth, led by General Hermann von Eichhorn , Armies set against the Russian Tenth Army, led by General Thadeus von Sievers. On February 7th, General Otto von Below launched a surprise attack against the Russian armies southern wing, advancing almost 70 miles in a week. As the Russians were falling back, they were attacked by the German Tenth Army on February 9th. The Russians became surrounded by the Germans in the Forest of Augustow and finally surrendered on February 21st. The Russians suffered 56,000 casualties and the Germans claimed 100,000 Russian prisoners.