Austria-Hungary’s Potiorek is pleased. In a month of tough fighting, his men have forced back the Serbs and obliged them to abandon Belgrade. He orders a victory parade through the Serb capital and starts to move forces eastwards, planning a great outflanking movement of the battered enemy.
But fortune never smiles on Austria-Hungary for long. The Serbs have received an unexpected arms shipment from France, allowing them to re-equip their army, which had been running out of ammunition and materiel. Now Putnik orders his men forward against the invaders. They catch the Austro-Hungarians by surprise. And the invaders are exhausted by the battles they have fought over the last month, yet so over-confident that they have not prepared good defensive positions.
The depleted Austro-Hungarian positions to the west of Belgrade take the brunt of the Serbian attack. The ferocious Serbs are unstoppable; the invaders break. News of the Serb counter-attack reaches Potiorek in Belgrade just as his men are making their victory parade through the city.
image source (Wikipedia)