The Austrian army, which had advanced into Poland was left in the air, and its retreat was transformed into a new disaster. Lemberg fell about September 1, 1914, and meantime a Serbian victory at the Jedar had destroyed still another Austrian army and emphasized the weakness of Hapsburg military power. (Vol. II, 329-335.)
At about the time the German blow at France was failing along the Marne, the Russian victories were mounting, Russian armies were sweeping through Galicia and approaching the San. (Vol. II, 398.) Serbian armies were across the Bosnia frontier, (Vol. II, 323), and the eastern situation was becoming perilous in the extreme for the Central Powers, despite the great victory of Tannenberg, which had cost the Russians an army of 100,000 men. (Vol. II, 438-450.) Thus in the first six weeks of the war the whole German conception had been defeated, France had not been destroyed by one great blow, and Russia had not been held up by Austria, pending the delivery of this blow and the return of the German troops who had delivered it.
October 24, 1914, The Battle of the Vistula.
October brought the plain necessity to the Germans of coming to the aid of their ally. While they were still endeavoring to reopen the decision in the west it was necessary to send troops to Hindenburg and to take pressure off Austria. The blow took the form of a rapid advance upon Warsaw through Central Poland, which was destitute of Russian troops. (Vol. II, 454-461.)
The thrust almost succeeded, German troops reached the suburbs of Warsaw, German guns were heard by the citizens of the town and Warsaw was in deadly peril, but Siberian troops arrived in the nick of time and Hindenburg was obliged to retire. (Vol. II, 462-466.) Still his main purpose was achieved. Russian armies in Galicia had been weakened to save Warsaw and were compelled to retire behind the San and the Vistula. (Vol. II, 420-427.)
Hindenburg's retreat was masterly, he flowed back upon Cracow and Breslau, pursued by a great Russian army. (Vol. II, 458-462.) Meantime the Russian armies in Galicia again took the offensive and November saw Russian armies at the outskirts of Cracow and approaching the boundary of Silesia. (Vol. II, 413-423.) Taken in connection with the German repulses all along the western front and the defeat in Flanders, which disclosed the final collapse of the original German plan, this moment marked the high-water stage of allied fortunes for many, many months.
Having led the Russian army after him to the German frontier, Hindenburg quickly moved his troops on strategic railroads to the north, invaded Poland again between the Vistula and the Warta (Vol. II, 462-481), almost succeeded in interposing between the Russian army and Warsaw, and won the great victory of Lodz. (Vol. II, 466, 467.) But Russian numbers saved the day. After terrific fighting and tremendous losses the Russians got back to the Bzura line, which they were to hold for nearly a year and the German advance was beaten down in fighting wholly similar to that in Flanders. (Vol. II, 471-478.)