When Crown Prince Alexander of Servia began the invasion of Bosnia in earnest, in the middle of August, Austria found herself at a disadvantage because of the necessity of massing most of her forces against the Russians. Roumania and Montenegro were then preparing to join the Servians in the field against Austria.
Later in August the Servians captured several of the enemy's strongholds in Bosnia. After a four-day battle on the banks of the Drina the Austrians were defeated with heavy loss, a large number of guns and prisoners being captured by the Servians. The Montenegrin troops repulsed an Austrian invading force and took several hundred prisoners in an all-day battle on the frontier.
Early in September a heavy engagement was fought by the Servian and Austrian armies near Jadar, resulting in Servian victory. It was claimed that the Austrians left 10,000 dead on the field of battle. The Servians also successfully defended Belgrade, which had been bombarded on several occasions. Fifteen or twenty miles west of Belgrade on the Save River, an Austrian force was decisively defeated by the Servians, who then seemed to be duplicating the successes of the Russian army against Austria.
The attitude of Turkey was being closely watched at this time, Greece and Bulgaria being prepared to enter the war against the Ottoman Empire if the latter decided on belligerency, but on September 5 Turkey again declared her intention to remain neutral.
SERVIANS CAPTURE SEMLIN
Crossing the Save River into Hungary, the Servians scored a brilliant stroke in the capture of Semlin, an important Austrian city. They also reported continued successes in Bosnia. Reports of wholesale desertions of Slavs from the Austrian army were received daily and probably had considerable foundation in fact. It was said that the Servians were being received enthusiastically by the people of Hungary.
These Servian triumphs led to the reorganization of the Balkan League, including Servia, Montenegro, Bulgaria and Greece.
On September 20 the Servian Government announced that an Austrian attacking army which attempted to cross the frontier near the Sabatz Mountains had been routed with a loss of 15,000 killed and wounded. The Servian losses in this and other engagements were claimed to have been small in comparison with those of the enemy.
Continuing their forward movement into Hungary, the Servians inflicted further losses on the Austrians near Noviapazow, while the Montenegrins reported a victory in the mountain slopes over their border.
On October 1 it was reported that the Servians had again repulsed an Austrian attempt at invasion and had driven the Austrians back across the Drina with loss. They had also checked another Austrian attempt to take Belgrade. The Servian war office claimed that the combined Servian-Montenegrin armies had made material progress in their invasion of Bosnia-Herzegovina, and that they were within striking distance of Serajevo, which they expected to capture. This, however, was denied by the Vienna ministry of war, which claimed that the Servian situation was entirely satisfactory to Austria.