1915: February 7
On February 7, 1915 German General Fritz von Below launched a surprise attack against the Russian army north of the Masurian Lakes on the Eastern Front. It was the second of two battles in the area; the first had taken place in September 1914 and had resulted in significant losses and a subsequent retreat for the Russian side. The orders for the second attack came from German Chief of Staff Erich Falkenhayn who, despite being reluctant to hand over resources to the east, believed a big win against Russia would give a good impression to potential Balkan allies.
The battle was launched during a heavy blizzard and the German forces quickly overwhelmed and nearly surrounded Russian lines. The Russian XX Corps, from the Russian Tenth Army, managed to hold off the German advance for two weeks before surrendering, long enough for three remaining corps to escape. While German losses were relatively low, the Russians suffered 56,000 casualities and an estimated 100,000 were taken prisoner. Despite what seemed like another blow to the Russian offensive, later attacks by the Russian Twelfth Army held back German progress and in the end the Second Battle of the Masurian Lakes had little strategic impact for the Central Powers.