some idea of the size of the campaign by considering the losses, which on the two sides amounted to a million men.

While these important events were taking place in Galicia, others of equal importance had occurred farther north.

The Russians, after their defeat by von Hindenburg at Tannenberg, retired across their frontiers, behind the Niemen River. German attempts to follow them failed. Then the Russians began a second invasion of East Prussia, advancing from their base at Grodno. The Germans, in too small force to take the offensive, contented themselves with defending their territory, and by the end of October, 1914, this second invasion came to an end. Then the Germans, having been reinforced, began a drive for Warsaw, which finally resulted, as we have seen in a previous chapter, in their capture of the Russian fortress of Lódz. Terrific fighting occurred for mile after mile east of Lódz, in the direction of Warsaw, all during the months of November and December, 1914, and January, 1915, but the Russians defended the city with the greatest bravery, and by the middle of February the fighting had died down, and Warsaw was still in Russian hands. In order to weaken the German drive against Warsaw, the Russians began, late in December, a counter-drive into East Prussia, thus for the third time invading that territory. Crossing the river Niemen, the armies of the czar

moved rapidly along the coast of the Baltic toward Königsberg, which had been threatened earlier in the year by the army of General Rennenkampf. Again General von Hindenburg was sent to drive them back, and there resulted one of the most terrible battles of the war, called the Battle of the Masurian Lakes. It lasted for nine days, from the seventh of February, 1915, to the sixteenth, although the pursuit of the beaten Russians continued for many days thereafter.

The

The Masurian Lakes are a chain of small bodies of water connected by wide stretches of marshland, interspersed by little streams all of which are covered with ice in midwinter, at which season the battle took place. The ground was thick with snow, drifted by high winds, and the conditions for military operations were extremely difficult. The German forces, under von Hindenburg, numbered at least a hundred and fifty thousand men. Russians asserted that they were double this. The exact number of Russian troops engaged is not known, but it probably was not less than two hundred thousand. Von Hindenburg put his guns and transport wagons on runners, and undertook successfully his favorite plan of outflanking the enemy and surrounding them. The Russians, not believing that they could be attacked in the midst of a violent snow-storm, neglected to keep proper watch, with the result that their right wing was surprised and overcome. A sudden attack upon

their left also drove that in, and the Russian armies fled in confusion. By the middle of February they had been completely driven from German soil, and during the retreat their losses were very heavy, large numbers being driven into the lakes and marshes, which had suddenly thawed, and drowned. The Germans contended that the Russians lost a hundred thousand men, these figures, however, being denied by their opponents. The fact remains that von Hindenburg gained a great victory, which heartened the German people at a time when, on both the western front and in Galicia, the war seemed to be going against them.

The success at the Masurian Lakes was soon followed up. In April a German army in turn advanced along the shores of the Baltic into the Russian province of Courland, and occupied the city of Libau. By the end of June this force had reached Mitau, just a little west of the great Russian port of Riga, on the Baltic. This quick advance, at the same time that von Mackensen and his armies were driving the Russians 'out of Galicia, was, as can readily be seen, a dangerous menace to the northern end or flank of the long Russian line. By the first of July the tremendous nature of the German campaign against Russia was apparent. In the extreme north the Russian flank, resting on the Baltic, was threatened. In the south German and Austrian armies were pressing the Russian forces back with huge losses. Now the Germans struck