To prevent the mobilization of the British armies, the Kaiser, after entrenching his forces on the French Front, sent all the troops he could dispose of against Calais. He felt so sure of success that he followed the operations in person, ready to enter as a conqueror into the city he expected to capture. He had acted in the same way two months before at Nancy; and having failed in that effort, he was eager for revenge. The French, British, and Belgian armies took care to transform his cherished revenge into a pitiful defeat. It was then that the German Command committed the mistake which will cause Germany to lose the war. Leaving the Western Front, giving to the French and British armies time to reorganize, arm, and gather strength, the Germans, having lost all hope of achieving the dreamed-of victories in the West, hurled their legions upon Russia, which they knew was insufficiently prepared, and began that campaign which was to result in their capture of Poland and the Baltic provinces, and the recovery of Galicia. The consequences of the adoption of this new plan were to be seen at once. At the beginning of the summer of 1915, in Artois, the French and British commenced to strike blows which proved that the strongest system of field fortifications can be taken. In September, 1915, General Pétain, in Champagne, inflicted a terrible defeat upon the Germans. This operation, carried out simultaneously with one in Artois, cost them thirty thousand prisoners, one hundred and fifty guns, heavy casualties, and--which is even of greater importance--obliged them to abandon highly valued and strongly fortified positions. In the beginning of 1916, having fulfilled their program in Russia, the German General Staff resolved to finish with the Western Front, and attacked Verdun with such enormous forces of artillery and infantry as had never before been known. Everywhere in Germany the announcement was made that the assault and capture of Verdun would bring the war to an end. Every one knows how vastly they were deceived. The French, taken by surprise and shaken at first, rallied rapidly. During five months they contested the ground inch by inch with a tenacity and heroism that stamps the defence of Verdun as the most sublime military feat recorded by History. The Germans did not take the fortress-city, but sacrificed in their attempt the very flower of their armies. Verdun had not exhausted all the strength of the French armies. On the first day of June, 1916, on the Somme, General Foch attacked the Germans so furiously that they had to suspend entirely their offensive against Verdun. On July 1st, the British Army, which had been developing to its final form and efficiency, took its place on the left of the positions of General Foch, and from that time on the Germans were forced to transfer most of their effectives to the Somme and the Aisne in order to oppose the Franco-British advance.