small forces at Goldap and near Gawaiten), and thus prepared for a movement next day in force by Wistyniec and Pilluponen on Wilkowiszki. On Sept. 13 the corps carried out this movement, preceded and flanked by the 8th Cav. Div. which had passed round the S. of Rominten Heath. The 3rd Res. Div. from Marggrabowa was turned eastward on Suwalki and, correspond- ingly, von der Goltz pushed forces up to Marggrabowa. On Sept. 13, indeed, the German army headquarters still hoped to cut off a considerable part of the Russian I. Army. But this hope was disappointed. Pushing his forces onward as fast as possible on Sept. 13, Francois was unable to do more than cannonade Russian columns which from time to time passed across his front. On Sept. 14 the Russians were found in force at Wilkowiszki, and both divs. of the German I. Corps had to be deployed to dislodge them. But they were a rear guard and not a flank guard, and since the pursuit thus became a frontal one for the I. Corps, as it already was for the rest, the battle of the Masurian Lakes as such came to an end.
Whether the direct follow-up should be continued to the Niemen or the operation closed down was a question of strategy, not of tactics. The latter alternative was chosen. On the night of Sept. 14 the German positions were: XI., XX. and XVII. Corps in the area round Stalluponen and Kibarty; I. Res. Corps at Wladislawow, with advanced forces to the N.E.; I. Corps and the cavalry at Wilkowiszki, with advanced troops at Mariampol and Pilwiszki; 3rd Res. Div. at Suwalki; the Guard Res. Corps was in reserve probably between Insterburg and Wehlau and the Konigsberg force had reoccupied Tilsit. The protective forces under von der Goltz, to the right rear of the 3rd Res. Div. and along the southern front, extended from Marggrabowa to the Vistula. The posts of this long, thin line were advanced considerably to the southward by frequent minor operations, of which the most important were a demonstra- tion against, and bombardment of, the defences of Osowiec by von der Goltz in the last ten days of Sept.; combats of the 35th Res. Div. about Mlawa, Sonsk, Przasnysz, Chorzele and Janowo (Sept. 12-21); and an expedition of the Thorn garrison, which captured Wloclawek on Sept. 21.
The German gains in the battle of the Masurian Lakes, although less than they had hoped for and not comparable with those of Tannenberg, were considerable. Rennenkampf had been beaten and forced back, if not in dissolution at any rate in disorder, practically to the Niemen. Strategic freedom had been secured to the Germans for a considerable time. East Prussia was cleared of the invaders, 30,000 unwounded prison- ers and 1 50 guns being added to the trophies of Tannenberg.
III. THE MASURIAN WINTER BATTLE
During Oct., Nov. and Dec. 1914, while the centre of gravity of operations on the Eastern European Front had lain in Poland and West Galicia, the German VIII. Army, much reduced, had defended the E. front of East Prussia against the Russian X. Army (Gen. Sievers), while the S. front had been held, in advance of the political frontier, by bodies and posts of Landwehr, Ersatz and Landsturm. In order to drive the Germans as far away as possible from the sensitive region of Kovno Grodno which they had approached in the battle of the Masurian Lakes, Sievers took the offensive in Oct. and Nov., and drove back the VIII. Army (commanded successively by von Schubert, von Frangois, and Otto von Below) to the line of the lakes, the Angerapp, and the Schoreller Forest, where the advance came to an end and both sides stabilized their positions.
In Jan. 1915 the German Higher Command decided to ree'n- force the E. front of East Prussia by the XXI. active and the newly formed XXXVIII., XXXIX. and XL. Res. Corps, and the S. front by various units drawn from Poland, in order to undertake a great offensive against the Russian lines of com- munication with Poland (of which the X. Army of Sievers was, substantially, a flank guard), while defending the southern front of E. Prussia against attack by the strong Russian XII. Army on the lower Narew. The strategic objects of this offensive are discussed under EASTERN EUROPEAN FRONT CAMPAIGNS; and
in the present article, which narrates the operations from the tactical point of view, it is sufficient to note that the envelopment of Sievers's right, combined with pressure on his front and the driving of a wedge into his left, was the immediate tactical idea, while the seizure of Osowiec and a bridgehead E. of the Bobr- Narew line for ulterior operations was the strategic object, which was to be attained in the act of driving this wedge, and secured by the doubje envelopment and destruction of the Russian X. Army. It was one of the most ambitious schemes attempted during the World War, and all the more so as it was to be carried out in midwinter.
The position of the Russian front line was as follows: Its right rested on the Szeszupa at the point where that river meets the frontier; thence it continued across the W. part of the Schoreller Forest to Spullen, where it turned due S., and, passing just E. of Gumbinnen and just W. of Goldap, followed thence a sinuous line amongst the lakes to Arys. From Arys southward it followed the E. edge of Lake Spirding and the line of the river Pissek (or Pissa) to the region of Lomzha. But S. of Lake Spirding, in advance of Johannisburg and Kolno, Russian light forces occupied most of the Johannisburg Heath, with a front E. of Rudczanny-Turoscheln-Friedrichshof, which, curving into the E.-W. direction, made contact with the line of the Russian forces facing the S. frontier. North of the right wing of the X. Army, i.e. of the lower Niemen or Memel river, were only small outposts of the minor Russian group based on Shavli.
In the last days of Jan. the German reenforcements assembled behind the screen formed by the VIII. Army. This screen, from right to left, consisted of Bacmeister's detachment (Landsturm) and the 3rd Cav. Bde. in the Johannisburg Heath, the 2nd Div. with 5th Inf. Bde., nth Landwehr Div., Lotzen garrison, ist Landwehr Div., 3rd Res. Div., loth and Konigsberg Landwehr Divs., and ist Cav. Div., with the 5th Guard Inf. Bde. as support. Of the reenforcements, three corps assembled behind the ist Cav. Div. screen, unobserved up to the last moment by the Russians, while the XL. Res. Corps joined the 2nd Div. behind Lake Spirding. The XX. Corps, brought from Poland to Ortelsburg, was to be pushed gradually by Myszyniec to the region between Johannisburg Heath and Lomzha, and so to broaden the wedge that it was to be the duty of the XL. Res. Corps and 2nd Div; to drive. In sum, a front line thinly and uniformly manned was secretly to be thickened at two points, on the right between Rudczanny and Kurwien, and on the left astride the Tilsit-Stalluponen railway. On the right, the " wedge " prepared behind the screen of Bacmeister's Landsturm consisted of 35 (eventually 5 to 55) divs.; on the left, the envelop- ing force prepared under cover of the ist Cav. Div. consisted of 6 to 65 divisions. The allocation of 10 young and homogeneous divisions, out of a total of 155 of all categories, to two attack sectors which together covered only 35 m. out of a uo-m. front, and the preparation of these masses behind a continuous line, mark the forthcoming battle, as compared with that of the Masurian Lakes, or even Lodz, as a first approximation to the typical World- War battle.
The VIII. Army and its reenforcements were formed into two armies, the VIII. (Otto von Below) having the front from the right to the Insterburg-Eydtkiihnen railway (its left unit be- ing the loth Landwehr Div.), and the X. (General-Oberst von Eichhorn) from that railway to the extreme left. General- Field-Marshal von Hindenburg and his chief of staff, Lt.-Gen. Ludendorff, moved " General Headquarters, East " to Insterburg so as to direct operations on the spot. The instructions given to Below and Eichhorn in the directives of Jan. 28 and Feb. 5 indicated only the general tactical idea without (so far as known) any allusion to the ultimate strategic objective, and left the army commanders almost a free hand. This was, no doubt, inevitable, owing, to the impossibility of regulating liaison in a rapid winter advance, but that very fact made it all the more desirable that the army commanders should be fully acquainted with the Higher Command's intentions. The sequel suggests that this was not the case. In sum, the directives laid it down that Eichhorn's left wing (from left to right, XXL, XXXIX.
