The advantage of "interior lines" which the Austrians enjoyed in this campaign had been partly discounted by the great size of modern armies and the time required to obtain the decision in a battle. It is true that the Germans were at this very period gaining brilliant successes by action on interior lines against Sam sonov and Rennenkampf in East Prussia, but their achievements were only rendered possible by the inertia of Rennenkampf. In Galicia, the continued pressure of Ruzski's and Brusilov's armies on the Austrian detaining wing denied to Conrad the time required to complete his successes in Poland. But the Austrian High Command appear to have depended too much on opportunist strategy. It is difficult to trace in their original organization for the campaign any recognition of the need for that "mass of manoeuvre," capable of being transferred from one wing to the other, which is the essence of action on interior lines. Also, the ineffectiveness for delaying action of their masses of cavalry deprived the Austrians of a powerful weapon. The Russian scheme of operations was straightforward and demanded only driving power by the higher commanders and hard fighting and marching by the troops. An opportunity of turning the Austrian retreat into a rout seems, however, to have been missed, when the Ix. Army from Warsaw directly reinforced the IV. Army instead of being directed west of the Vistula on the Austrian line of retreat.
The Battles of 1915.—The fighting which led up to the second series of battles round Lemberg in the summer of 1915 is described under the heading DUNAJEC-SAN. After being driven from the San, the Russian III. Army (now under Lesh instead of Radko Dimitriev) and VIII. Army (Brusilov) took up a position to the north-west and west of Lemberg. Their line ran from the Vistula along the heights north of the Tanew river, thence west of Rawa-Ruska by MagierOw and JanOw to the Wereszyca river and GrOdek lakes. The XI. and IX. Armies continued the line south-east along the Dniester.
Mackensen's pursuing force consisted of the Austrian IV., German XI. and Austrian II. Armies, in that order from north to south. On the Dniester were Linsingen's Southern Army and Pflanzer-Baltin's VII. Army. In the number of available forma tions there was no great disparity between Mackensen's group of armies and the Russian III. and VIII. Armies; on each side there were about 4o infantry divisions, and the Russians had five or six cavalry divisions to Mackensen's two. But the two Russian armies now embraced an improvised assembly of formations and units taken from all parts of the line; even so their losses had not been made good and they were much under strength ; there was a shortage of ammunition, both for guns and rifles; and morale had suffered under two and a half months of continual defeat.
As usual, the main thrust at the Russian position was delivered by the German XI. Army. It was directed through MagierOw against the line ZOlkiew-Rawa-Ruska, approximately at the joint between the Russian III. and VIII. Armies. The assault was made on June 19, after the Russian position had been battered by the German guns, and the attackers broke right through to the Rawa-Ruska-Lemberg railway. Brusilo v held on to a fortified position west of Lemberg till the 22nd, and then evacuated it under the threat that came from the north and the direct pressure from the Austrian II. Army.
The Russian armies were now split apart; the VIII. Army retired fighting to the line of the Upper Bug and Gnila Lipa; at the same time the XI. and IX. Armies gave up the Dniester line below Halicz. The III. Army meanwhile, to protect the left flank of the Warsaw salient, was forced to retire north towards Lublin and Chelm. To fill the gap between the III. and VIII. Armies, a new army, the XIII. under Gorbatovski, was formed of troops drawn from the right of the III. Army and left of the VIII. The Austrian armies were also re-grouped; the II. Army, the Southern Army and VII. Army were to continue the pursuit eastwards; Mackensen with the IV., XI. and a new "Army of the Bug," to be formed under Linsingen, was to strike northwards between the Bug and Vistula ; while the I. Army, withdrawn from the west of the Vistula, was to fill the gap between the two army groups.
The Eastern group drove the Russians back at the beginning of July from the Gnila Lipa to the Zlota Lipa; no further fighting took place here till the end of August. Farther east, Pflanzer Baltin's VII. Army and Lechitski's IX. were engaged in an in decisive conflict along the Dniester between July 14 and 19. Meanwhile on Mackensen's front the Austrian IV. Army had been heavily counter-attacked near Krasnik by the Russian IV. Army and had been driven back some distance, losing 17,000 prisoners. The check was only temporary, and so soon as the re-grouping was completed, Mackensen again advanced. For further operations of this force, see BREST-LITOVSK, BATTLES OF.