leaned to the left on the lower Niemen, rather east of Tilsit. In March there had been some advances and retreats on both sides but no substantial change in the situation. A raid on Memel, beyond the left flank of Eichhorn's Army, by a small body of Russian militia from Libau (who were expelled after doing some damage) was the only incident of importance N. of the Niemen till, in mid-April, Hindenburg received orders to deliver feint attacks in order to divert attention from the forth- coming Gorlice offensive. He chose, for this purpose, the region N.E. of Tilsit, and formed a mobile army group of infantry and cavalry divisions under General von Lauenstein. In this quarter the Russians had only small forces, and the advance could be carried out in three separate columns, thus covering an enormous front. In all, 3 infantry and 3 cavalry divisions were sent out on April 27, by Memel toward the Vindava, by Tauroggen on Shavli (Schaulen, Szawle), and by Yurburg on Sredniki and the Dubissa line. A small raiding body, in conjunction with light naval forces, took possession of Libau early in May.
Lauenstein's movement was unexpected, and his left column penetrated to Mitau before the reaction set in. The others made good Shavli and the line of the Dubissa, and during May and June a series of fierce battles on a small scale took place all along this line. The Russians brought up considerable reinforce- ments under the V. Army staff, and the first object of Lauenstein's enterprise thus attained marked success. But, like other wide extensions of front in the war, as soon as serious infantry fighting opened, manoeuvre began to call upon reserve resources for its maintenance. Two infantry and 2 cavalry divisions were added to the German force, which became the " Army of the Niemen " under Otto von Below, Scholtz succeeding this officer as the head of the VIII. Army. Thus, at the end of June, when the plan of future operations was being settled, the ground was prepared for the manoeuvre advocated by Ludendorff. From Shavli, with flank guards set out successively towards Riga and Dvinsk, the Niemen army could, after being made sufficiently strong to defeat the Russian V. Army assembled in front of it, turn Kovno and reach the Vilya line long before the Russians in retreat from western Poland could do so. On the other hand, so grave a peril would clearly bring into existence a new Russian army of relief in the Riga-Dvinsk-Petrograd region, and this army would make short work of a few flank-guard divisions facing Riga, Jakobstad and Dvinsk. One necessary condition of Ludendorff's plan, therefore, was heavy reinforcement of the Niemen army; another 'the reduction of Kovno, so as to clear a direct and safe line of communications Insterburg-Vilna and to bring the X. Army into action E. of the Niemen. From Falkenhayn's point of view, however, the eccentricity of the whole manoeuvre was its gravest drawback. He doubted whether so distant an operation would affect the situation of Mackensen, but especially whether it would not become just that plunge into the unlimited interior of Russia which, with his time-limit fixed, he dreaded above all. Operations N. and E. of Kovno were permissible, in his opinion, only for hunting down an army already in dissolution, not as a preliminary to the battle that was to bring about that dissolution.
Such, in sum, were the elements of a controversy between Falkenhayn and Ludendorff, which in the course of the summer created a serious breach between the Supreme Command and the commander-in-chief East, and undoubtedly handicapped the operations, for Falkenhayn never swerved from his intention to close down the campaign as soon as an " adequate " result had been achieved, and Ludendorff on his side returned to the charge at every opportunity, with the result that the few available reserves were handled without singleness of purpose.
The Ludendorff plan, first proposed as early as June 7, was discussed fully at a conference on July 2, in the presence of the Emperor William, who, bound by the practice of the German army either to follow the counsels of his sole and responsible adviser or to dismiss him, chose the former course.
It was decided therefore that Mackensen, after completing his wheel-up, should advance with all possible energy against his immediate opponents between the Vistula and the Bug,
with the reconstituted Austrian I. Army protecting his right flank by making good the line of the upper Bug as he advanced; and that Gallwitz's army group, reinforced, should break through at Przasnysz and on the Narew. When Gallwitz's operation, with its immediate relief to Mackensen, should have been completed, then Falkenhayn was prepared to allow an extension of the offensive to the middle Niemen region.
On Mackensen's front the wheel-up was completed in the midst of a heavy Russian counter-attack, and the advance that was to follow was involved in great difficulties from the outset. His three armies from left to right, the Austrian IV. and the German XL "and Bug Armies (the last newly formed under Linsingen) had not moved appreciably when Gallwitz's attack was delivered. The Russians had massed considerable forces to deny access to the inner gates of the corridor, and under cover of their activity had already begun the evacuation of the central salient. There all the old line had been already given up S. of Inowlodz on the Pilica, and, on Mackensen's intention becoming evident, the retreat was continued to the line of the Vistula itself, where, however, the foreground of Ivangorod and, especial- ly, the great entrenched positions west of Warsaw continued to be held in force. The German IX. and Woyrsch Armies in front of this line, now constituted as a group of armies under Prince Leopold (probably in order to give Falkenhayn a force independ- ent of both Hindenburg and Conrad), had been weakened and could do little more than follow up, boldly on the right but very cautiously on the left where the Warsaw positions and Novogeorgievsk imposed respect.
When Woyrsch reached the region of Ivangorod (July 21) so little progress had been made on the Mackensen front that Conrad proposed that Woyrsch should cross the Vistula above that fortress, so as to intervene in rear of Joseph Ferdinand's opponents. This movement, which would have thrown the axis of Woyrsch, and eventually that of the IX. Army also, away from the region of the middle Bug and put an end to all hopes of cutting off the Warsaw group of the enemy, was opposed by Falkenhayn and also by Mackensen, and Woyrsch received orders to cross the Vistula below Ivangorod, as he did on the night of July 28-29 near Muciejowice. The IX. Army mean- while felt its way forward to the Warsaw lines and the S. front of Novogeorgievsk.
Before any of these movements were under way largely indeed with the intention of helping them to get under way the Gallwitz group, reinforced from the central salient by 4 divisions to a strength of about 1 5, had opened its offensive on July 13-16 by breaking through the Russian XII. Army's trench-lines at and west of Przasnysz (see NAREW, BATTLES OF THE). On the night of the I7th Gallwitz stood within range of Ostrolenka on the left and the N. defences of Novogeorgievsk on the right. But a new and more severe effort was needed for the forcing of the Narew line itself. Russian counter-attack forces arrived in time, and it was only on Aug. 8 more than 3 weeks after the offensive began that the Gallwitz group, now styled XII. Army, had made good a line E. of the river defined by Serock-Wyszkow (on the Bug)-E. of Ostrow-R. Ruz, the last named being occupied by the right of Scholtz's VIII. Army which had advanced in sympathy. The right of the German XII. Army meantime, W. of the Narew and facing S., was holding its own, not without considerable difficulty, against repeated counter-attacks issuing from the Novogeorgievsk defences, where the Grand Duke maintained large mobile forces up to the eleventh hour and indeed beyond it.
In these 3 weeks Mackensen's right, the Bug Army, had been engaged (see BREST-LITOVSK, BATTLES OF) by the Russian XIII. Army, at the halt on almost every line of E.-W. streams avail- able. It had fought on the line Grabowiec-Grubieszow from July 10-21, on that of Chelm-Annopol from the 2ist to the3ist, and along the Ucherka river and at Sawin in the first days of August. The XL Army, with better conditions, had advanced first astride and then east of the Huczwa, and by Aug. 6 had reached Lubartow-Sawin; while Joseph Ferdinand had without the suggested flanking assistance from Woyrsch reached the
