During the two weeks following the fall of Nish the three commanders of the invading armies began, and continued, a great converging movement on the Kossovo Plain, their object being to completely encircle the main Serbian armies. Kövess was advancing his forces toward Mitrovitza on the north side of the plain from Kralievo up the valley of the Ibar, branching out of the Western Morava. In the hills north of Ivanitza the Serbian rear guards made a stubborn attempt to hold him back, but finally they were dislodged and the Austrians occupied Ivanitza on November 9, 1915. Four days later, after driving the Serbians from their intrenchments in the Stolovi ranges, he reached Rashka, which had been the seat of the Serbian Government after its flight from Kralievo and which was situated on the Ibar, some distance along the road to Mitrovitza and only a few miles from Novi Bazar. This place he took on November 20, 1915, and with it a small arsenal, in which were fifty large mortars and eight guns, which even the German reports described as of "somewhat ancient pattern."
To the eastward the Austrians had taken possession of Sienitza and Novi Varosh, up toward the Montenegrin frontier. Being expelled from Zhochanitza, the Serbians retired to Mitrovitza. By November 22, 1915, the Austrian lines had followed to within five miles of that point.
Gallwitz and his Germans, in the meanwhile, operating on the left flank of the Austrians, was pushing southward, his object being to take Pristina, on the east side of the Kossovo Plain and about twenty miles southeast of Mitrovitza. But this was a task that could not be accomplished without much difficulty, for before him towered the backbone of Serbia's main mountain ridges, each ravine and each ledge sheltering strong Serbian forces.
As usual, however, the big guns cleared the way before Gallwitz, though at Jastrebatz the Serbians made him pay a heavy price in the losses he suffered. On this front the Bulgars were now coming close enough to the Germans to support them; against the two the Serbians had not the slightest chance.
By November 8, 1915, Gallwitz was starting out from Krushevatz, after which he followed the banks of a small branch of the Western Morava in a southwesterly direction, toward Brus, with one part of his force, another being sent due south across a range of high hills toward Kurshumlia. He soon reached Ribari and Ribarska Bania, where the retreating Serbians gave him what he himself described in his official report as "very stiff fighting." Next he stormed the pass through the mountains and thus gained an entrance to the valley of the Toplitza, through which flows a river westward into the Morava, the main stream by that name, though in this district it is known as the Southern Morava.