A laconic announcement of the German General Staff on July 14, 1915, bore momentous news, although its modest wording scarcely betrayed the facts. It read: "Between the Niemen and the Vistula, in the region of Walwarga, southwest of Kolno, near Przasnysz and south of Mlawa, our troops have achieved some local successes." The Russian report referring to the beginning of the same action was equally noncommittal, though possibly more misleading. This states: "Considerable enemy forces between the Orczy and the Lidynja adopted the offensive and the Russians declining a decisive engagement retreated during the night of the 13th to the second line of their positions."
On July 15, 1915, the Germans announced that the city of Przasnysz, for which such hot battles had been fought in February, and which had since been strongly fortified by the Russians, had been occupied by them. The German summary of this action given out a few days later stated that three Russian defensive lines lying one behind the other northwest and northeast of Przasnysz had been pierced and taken, the troops at once rushing forward to Dzielin and Lipa, respectively west and east of the town. Under attack from these two points the Russians after yielding Przasnysz, on the 14th, retired to their defensive line Ciechanow-Krasnosielc which had been prepared long beforehand. On the 15th the German troops pressing closer upon the retiring Slavs stormed this line and broke through it to the south of Zielona on a breadth of seven kilometers, forcing the Russians again to retire. General von Gallwitz's troops in this assault were supported by the forces of General von Scholtz, on their left, who were pressing the Russians from the direction of Kolno. On July 16, 1915, the Russians were retreating on the whole front between the Pissa and the Vistula, toward the Narew.
The German summary of the fighting during these days reported the capture by the army of General von Gallwitz of eighty-eight officers, 17,500 men, thirteen cannon (including one heavy gun), forty machine guns, and seven mine throwers; and by the army of General von Scholtz of 2,500 prisoners and eight machine guns.
This great attack in the north, to which may be ascribed the final breaking of the lines that had so long protected Warsaw, had been carefully planned and undoubtedly was timed in coordination with the movements of Mackensen's armies on the south, striking the Russians just when Mackensen and the Archduke Josef, having had time for recuperation and preparation for another push forward after the check administered at Krasnik, were in readiness to inflict a heavy blow on their side of the Warsaw salient. When it began the German lines all along the front burst into fresh activity. It was the signal for a simultaneous assault along nearly a thousand miles of battle front.
In the Mlawa sector to the north of Przasnysz the Russians had developed an exceedingly strong system of fortified positions between their advance lines and the Narew fortresses. For miles, to a depth of from fifteen to twenty kilometers, there ran some three or four and at certain points even five systems of trenches, one behind the other. Hundreds of thousands of thick tree trunks had been worked into these defensive works and millions of sand bags piled up as breastwork. Bombproof dugouts had been constructed deep in the ground. Everywhere there were strong wire entanglements before the front, sometimes sunk below the level of the earth, arranged in from two to three rows. Projecting bastions and thoroughly protected observation posts gave these systems of trenches the character of permanent fortifications.
The country in this region is hilly, with here and there steep declivities and peaks of considerable elevation. The Russians had cut down whole stretches of forest in order to afford them a free field for their fire and an opportunity to observe the advance of their opponents. Enveloping tactics on the part of the Germans were here quite excluded as the two lines ran uninterruptedly close to one another. Przasnysz which had become a heap of ruins had been converted virtually into a fortress by strong defensive works built while the Germans and Russians lay opposite each other in front of it throughout the spring. The country round about had been drenched with much German and Russian blood.
General von Gallwitz, to capture a place with the least possible loss, decided to break through the Russian defenses at two points at both sides of the town sufficiently close to each other so that the intervening lines would be immediately affected. His attacks were therefore directed at the first line Russian positions, which formed projecting angles to the northwest and northeast of Przasnysz so that instead of taking the city directly from the front he would seize it as with a gigantic pair of pincers from both sides and behind. The plan succeeded to the full. The Russian lines were broken on both sides of the city and the German troops, rushing through, met behind it, forcing the Russian defenders hastily to evacuate the place to avoid being caught within the circle.
Strong infantry forces were collected opposite the points of attack, and enormous masses of artillery were placed in position with abundance of ammunition in readiness. The preparations had been made with all possible secrecy and even when the German batteries had begun gradually to get their range by testing shots no serious assault seems to have been expected by the Russians. On the morning of the attack they were just to inaugurate service on a small passenger railway line they had constructed behind their front.
On the morning of July 13, 1915, soon after sunrise, a tremendous cannonade was let loose from guns of all calibers. Although the weather was rainy and not well fitted for observation the German guns seem to have found their marks with great accuracy. When the German infantry stormed the first line of works which had been shattered by the artillery fire they met with comparatively little resistance and their losses were small. The bombardment apparently had done its work thoroughly. The German infantry rushes were started in successive intervals of a quarter of an hour, line following line. Swarms of unarmed Russians could be seen coming out of the trenches seeking to save themselves from the terrible effect of the shell fire by surrendering. During the course of the forenoon the sun came out and illuminated a scene of terrific destruction. The Russian positions on the heights northwest of Przasnysz had been completely leveled. In their impetuous forward rush the German troops did not give the enemy time to make a stand in his second line of trenches and overrunning this, by night began to enter the third Russian defensive line. Przasnysz was flanked in the course of twenty-four hours and could no longer be held. A fine rain was falling as the German columns marched through the deserted, smoke-blackened city, a melancholy setting for a victory.
On July 14, 1915, the German troops had broken through on both sides of the city, met to the south of it and forming a mighty battering ram, on the next day, forced the next Russian line, the last, to the north of the Narew. This ran through Wysogrod-Ciechanow-Zielona to Kranosiele. The Russians here made a desperate defense and the German advance pushed forward but slowly. The effect of the German artillery fire seems not to have been as striking as on the first day of battle. The German report of the attack on this line points out that the regiment of the Guard holding the right wing of a division which was to attack the heights to the south and southeast of Zielona was impatient to go forward, and was allowed to advance before the reserves which were to be held in readiness to support the move had come up.