The Austrian commander-in-chief proposed to turn the Serbian left, and at the same time hurry forward mountain troops to Valjevo, and thus cut off the retreat of the Serbian army. During September and October attacks and counter-attacks were constant, but neither side made much headway. The Austrians could not drive the Serbians off the crests of the mountains, and the Serbians could not drive back the Austrians, who were advancing up the Drina to turn the Serbian left. At length, however, the Serbian ammunition began to fail, and the Austrian numbers began to tell. On 6th November the enemy won the summits of the Tser Mountains, and the Serbians, in order to avoid being enveloped, were forced to retreat eastwards. This they did in perfect order. [Illustration: Map to illustrate the Campaign of November and December 1914.] The Austrians pushed on, and occupied Valjevo on 14th November. While the Serbians retired to the summit of a range south of Valjevo, the invaders pillaged the whole Kolubara valley and their line of march was marked by fire and massacre. Belgrade was abandoned, and on 2nd December the Austrians made a state entry into the undefended capital. Telegrams of congratulation were sent to old Franz Josef, and Vienna was full of rejoicing. The Austrians boldly declared that the campaign was over, that the Serbians were finally defeated, and that the fruits of victory were about to be reaped. So certain of success was the Austrian general that he sent back three of his corps to help his fellow-countrymen, who were now about to begin their attack on the Carpathian passes from the south. For a whole fortnight the Austrians dallied in Valjevo and on the skirts of the ridges occupied by the enemy. During this period the Serbians were by no means idle. Every available man was brought up, gun positions were prepared, and trenches were dug and strengthened. Best of all, the Western Allies sent them ammunition for big guns and small arms, and these supplies now reached the hard-pressed Serbians, despite the efforts of Turkish and Bulgarian bands to capture them. [Illustration] Serbia was about to make her last stand. Everything had to be staked on the issue of the coming battle. If the Serbians should be driven back they would be almost certain to lose Kragujevatz,[179] their arsenal and chief industrial centre, and without it they could scarcely continue the struggle. They would also lose Nish, the old capital, now the sojourning place of the government. The Serbians, however, held a very strong position on the Maljen ridge, to the west of the main road leading from Valjevo to Kragujevatz, and were also posted on the still higher Rudnik ridge to the east of this road.