Great masses of Germanic reserves were concentrating in northern Hungary, into which the Russians had driven a thin wedge south of Dukla, where they held an isolated outpost near Bartfeld. To leave this position undeveloped meant compulsory withdrawal or disaster. With the continual influx of reenforcements on both sides, the struggle for the main passes gradually develops into an ever-expanding and unbroken battle front: all the gaps are being filled up. From Dukla westward to the Dunajec-Biala line and the Carpathian foothills a new link is formed by the Fourth Austrian Army, commanded by the Archduke Joseph Ferdinand, with two and a half army corps and one German division. In the Central Carpathians a fifth army, under the command of the Austrian General von Bojna, appears between the forces of Boehm-Ermolli and those of Von Linsingen. Right away eastward the purely Austrian army of Von Pflanzer-Baltin was holding the Pruth Valley. The Germanic chain was complete, with every link welded together.
When the Russian offensive opened on March 19, 1915, the entire battle line still rested on the northern side of the Carpathians, and here the struggle was resumed. The Russian grand attack was directed between the Lupkow and Uzsok passes, where great forces of the enemy, concentrated for the purpose of relieving Przemysl, were stationed. In the western sector, facing Dmitrieff, the Archduke Joseph Ferdinand held the roads leading from Novy-Sacz and Grybow to Tarnow, covering Cracow; and from south of the range the two roads diverging from Zboro to Gorlice and Jaslo were in Russian possession, though the Austrians held their junction at Zboro, eight miles north of Bartfeld. Of the actual fighting that took place in this region very few details were published by the Russian official communiqué. One of these documents, dated April 18, 1915, announced that on March 23, "our troops had already begun their principal attack in the direction of Baligrod, enveloping the enemy positions from the west of the Lupkow Pass and on the east near the sources of the San. The enemy opposed the most desperate resistance to the offensive of our troops. They had brought up every available man on the front from the direction of Bartfeld as far as the Uzsok Pass, including even German troops and numerous cavalrymen fighting on foot. The effectives on this front exceeded 300 battalions. Moreover, our troops had to overcome great natural difficulties at every step. In the course of the day, March 23, 1915, we captured more than 4,000 prisoners, a gun, and several dozen machine guns."