To protect Insterburg, General van Francois made his first stand at Gumbinnen, where, on the 16th of August, the first important battle of this campaign took place. The result was the defeat and retirement of the Germans, and von Francois was forced to fall back on Koenigsberg. Meantime, the Army of the Narev, under General Samsonov, was advancing through the country west of the Masurian Lakes. On the 20th his vanguard came upon a German army corps, strongly entrenched at the northwest end of the lakes. The Germans were defeated, and fled in great disorder toward Koenigsberg, abandoning their guns and wagons. Many prisoners were taken, and the Russians found themselves masters of all of East Prussia except that inside the Koenigsberg line. They then marched on Koenigsberg, and East Prussia was for a moment at the mercy of the conqueror. Troops were left to invest Koenigsberg, and East Prussia was overrun with the enemy. The report as to the behavior of these troops met with great indignation in Germany; but better information insists that they behaved with decorum and discretion. The peasantry of East Prussia, remembering wild tales of the Cossacks of a hundred years before, fled in confusion with stories of burning and slaughter and outrage. Germany became aroused. To thoroughly understand the effect of the Russian invasion of East Prussia, one must know something of the relations of that district with the German Empire. Historically, this was the cradle of the Prussian aristocracy, whose dangerous policies had alarmed Europe for so many decades. The Prussian aristocracy originated in a mixture of certain west German and Christian knights, with a pagan population of the eastern Baltic plain. The district was separate from Poland and never fell under the Polish influence. It was held by the Teutonic knights who conquered it in a sort of savage independence. The Christian faith, which the Teutonic knights professed to inculcate, took little root, but such civilization as Germany itself had absorbed did filter in. The chief noble of Borussia, the governing Duke, acquired in time the title of King, and it was here, not in Berlin, nor in Brandenburg, that the Hohenzollern power originated. [Illustration: Painting] THE FURY OF A COSSACK CHARGE Some of the most bitter fighting of the war took place on the snow-covered heights of the Carpathians when Russia's armies struggled with the foe. Here is illustrated a charge by Cossacks on an Austrian battery. There is nothing in warfare quite like the furious onslaught of the little men of the steppes on their wiry ponies. [Illustration: Painting] HIDE AND SEEK IN THE BALTIC A Zeppelin flying over a British submarine in the stormy sea. [Illustration: Map bounded by Koenigsberg on the North, Warsaw on the East, Cracow on the South and Posen on the West.] THE EASTERN FIGHTING ZONE