favorable railway
connections. Two railways terminating at Ostrolenka permitted the
rapid unloading of large masses of troops at this point, and the line
Warsaw-Mlawa-Soldau led straight into the territory aimed at by such
an invasion. It seemed easily credible that the Russian commander in
chief did, as reported, give orders that Mlawa should be taken be the
cost what it might.

The northern Russian armies based upon the fortresses of Kovno and
Grodno on the Niemen had not fully started on their part of this great,
well-planned undertaking when the German counteroffensive was suddenly
launched with tremendous strength from the Tilsit-Insterburg-Mazurian
Lakes line. The disaster which followed, and which banished all hope of
an advance of the Russians on this wing, has been described on a
preceding page. While the Germans, using to the best advantage their net
of railroads for the swift accumulation of troops, had gathered large
forces on the Mazurian Lakes line, they had at the same time
strengthened the troops standing on the southern boundary of West and
East Prussia. An artillery officer, General von Gallwitz, was placed in
command of this army with orders to protect the right flank of the
German armies attacking in Mazurian Land, and to prevent the expected
Russian attempt at invasion in his own sector of the front.

While the "winter battle" was raging to the east of him, Von Gallwitz
in the characteristic German fashion of defense by a strong offensive
moved forward up the right bank of the Vistula to Plozk. A cavalry
division and regiments of the Guard at Sierpe and Racionz, February
12-18, 1915, won well-earned laurels for themselves by driving an
enemy of superior strength before them. At Dobrin, according to German
report, they took 2,500 prisoners.

General von Gallwitz's plan, however, was of more ambitious scope. It
was his intention, by encircling the Russians in the territory before
him from both wings, to sweep clear of enemies the entire stretch of
country in the Polish triangle between the Vistula and the Orczy
rivers. The right wing of his troops that had come down the bank of
the Vistula was to swing to the eastward in behind the Russians.
German troops which had arrived at Willenberg inside of the East
Prussian boundary, one of the German concentration points on the line
of railroad lying behind their front, on the other hand, received
orders to descend the valley of the Orczy and to come in beh