To check the onslaught of the reinforced Russian armies against the Carpathian passes early in April, troops must be drawn from General von Hindenberg's armies, and the consequence was another deadlock in the north. Meanwhile the reinforced Teutonic troops were hurriedly concentrated for the counter-attack against the Russian offensive in the Carpathians, and a great drive began against the Russian positions on the Dunajec line, east of Cracow, early in May. Breaking all resistance, it swept on toward Jaroslau and Przemysl on a sixty-mile front. Threatened in their right and left flanks, respectively, the Russian lines on the Nida and in the Carpathians fell back rapidly, while reinforcements were sent to stem the Teutonic advance along the San. But the Russian efforts were in vain. The momentum the Teutonic offensive had gained carried it across the river, while further south the Austrian right wing cleared the entire Carpathian front of the enemy, hotly pushing his retreat. Przemysl was recaptured, the third Russian line of defense from Rawa-Ruska to Grodeck and the Dniester was broken, and the end of June saw Lemberg once more in the hands of the Teutons, and the Russian line on the defensive and sorely pressed along a front extending from the Bessarabian frontier along the Dniester to the mouth of the Zlota-Lipa, and from there along the Zlota-Lipa and the Bug, well into Russian territory, leaving the river southeast of Grubeschow, and continuing from there in a northwesterly direction to the region of Krasnik. Here it joined hands with the left wing of the Russian Army of the Nida, which had retired before the Austro-German advance in a northeasterly direction, intrenching along a line from Krasnik across the Vistula and through Sjenno and Jastrshob (about fifteen miles southwest of Radom) to the region of Tomaschew on the Pilitza. While this great Spring offensive from the Dunajec line was well under way, small German forces invaded the Russian province of Courland. Finding at first little resistance in the path of their unexpected advance, they took Libau and established themselves on the Dubissa-Windau line. During July the operations in Courland steadily assumed greater proportions. Two bases for the campaign against the Russian lines of communication have thus been firmly established in the flanks of the Russian Armies west of the Vistula, both protruding far into their rear. Drives against the Dunaburg-Warsaw line from the north and the Minsk-Ivangorod line from the south will open the second year of the eastern campaign. The first year of the incessant struggle has brought the aims of the German strategy, the bagging of the Russian Armies, within sight of its realization. III. CAMPAIGNS OF MINOR IMPORTANCE