During the night of May 11, 1915, and the next day they evacuated a front of about eighty-eight miles, and retired south of the Pruth. General Mishtchenko led his Cossacks on the Austrian trail, taking several towns on their way to Nadvorna, which they captured after a fierce fight. From here they took possession of part of the railway line from Delatyn to Kolomea, and completely severed the connection between Von Pflanzer-Baltin's forces and those of Von Linsingen lying along the north of the range. Larger bodies of Russian troops were on the way to Kolomea; on May 13, 1915, they stormed and carried some strongly fortified Austrian positions eight miles north of the town, in front of which the Austrians had placed reenforcements and all their last reserves. By dint of great efforts they held their position here, but from May 9 to May 14, 1915, the Russians drove them back elsewhere on a front of over sixty miles for a distance of about twenty miles, also capturing some 20,000 prisoners with many guns and valuable stores of munitions. About the middle of May matters quieted down in the eastern sector; the only fighting of importance consisted of severe artillery combats around Czernowitz and Kolomea. The issue of the conflict hung in the west with Von Mackensen's armies; fighting in the Bukowina at this stage became an unnecessary expenditure of strength and energy. The fate of eastern Galicia was being decided 140 miles away, on the banks of the River San, to which region we will now direct the reader's attention. CHAPTER XLIV RUSSIAN CHANGE OF FRONT--RETREAT TO THE SAN After the Russian troops retreated from the Lower Wisloka northward toward the confluence of that river with the Vistula they held the two important bridgeheads of Sandomierz and Rozvadov.