In a way the victory at Brest-Litovsk was an empty one, for the Russians apparently had decided that the fortress would become untenable before long and had withdrawn from it in good time not only practically the entire garrison but also whatever supplies or equipment they could possibly transport, destroying most of what they were forced to leave behind and blowing up many of the fortifications. The strategical value of the victory was, of course, not influenced by this action. After the fall of the fortress the combined forces of the Germans and Austrians did not rest on their laurels. Without wasting any time they immediately took up in all directions the pursuit of the retreating Russians. For a short time the retreating Russian troops made a determined stand in the neighborhood of Kamienietz-Litovsk, northeast of Brest-Litovsk, but could not withstand the German pressure for long. A great deal of very heavy and bloody fighting took place in this period, August 25 to August 31, 1915, in the dense forest south of Bialystok and east of Bielsk, sometimes known as the Forest of Bialystok and sometimes as the Forest of Bielovies, a little town at the end of a short branch railroad, running east from Bielsk. The Upper Nareff flows through this forest and much of the fighting was along its banks. Austrian troops, a few days earlier, had reached Pushany, just north of the Brest-Litovsk-Minsk railroad and from there pressed on in an easterly direction. By August 21, 1915, the Upper Nareff had been crossed after the hardest kind of fighting on both sides, and the advance continued now toward Grozana. It was not, however, until September 1, 1915, that these troops were able to fight their way out of the forest. At the same time Von Mackensen's troops were following the retreating Russians into the Pripet Marshes. Other parts of this group which had advanced east from Brest-Litovsk along the Minsk railroad reached the Jasiolda River, a tributary of the Pripet, at a point near Bereza, while Austro-Hungarian troops forming part of Von Mackensen's army advanced to east and south of Boloto and Dubowoje. Further north, Prince Leopold's army was still fighting the retreating Russians just north of Pushany, but on September 4, 1915, finally fought its way out of the marshes which--outrunners of the vast Pripet Marshes--are abundant in that region.