Battle of Kolubara

Background

By the autumn of 1914 Serbia had already beaten two Austro-Hungarian invasions, at the Cer in August and, after Serbia's own thrust into Bosnia, on the Drina in September. The Dual Monarchy's military command nevertheless authorised a third invasion in early October, with the aim of taking Niš, Serbia's wartime capital. Oskar Potiorek's 6th Army and Liborius von Frank's 5th Army crossed the Drina on 6–7 November.

Serbia was desperately short of artillery, ammunition, rifles and uniforms; about 50,000 men would have lacked equipment on full mobilisation, and the Austro-Hungarians had roughly twice as many field guns and machine guns. The chief of the general staff, Radomir Putnik, therefore traded ground for time. On 10 November he ordered a general retreat from the Jadar, and the army fell back through what he reportedly called Serbian national mud, destroying bridges and telephone lines. The Austro-Hungarians entered Valjevo on 15 November and reached the Kolubara on 16 November. Putnik had fortified the Jeljak and Maljen mountains in October, and France sent shells, though Russia and Britain offered only understanding.

The battle was fought in two halves: a Serbian retreat under pressure, then a sudden counter-offensive in early December that turned a lost campaign into a decisive victory.

The armies

Wikipedia's account puts about 400,000 Serbian troops, in the 1st, 2nd and 3rd Armies and the Užice Army, against some 450,000 Austro-Hungarians in the 5th and 6th Armies. The Serbian army was nominally led by Crown Prince Alexander, but Putnik was its real directing mind. Under him Stepa Stepanović led the 2nd Army, Pavle Jurišić Šturm the 3rd and Miloš Božanović the Užice Army. The 1st Army passed from the wounded Petar Bojović to Živojin Mišić, who pressed for a deep withdrawal to rest the troops and shorten the line, and Putnik eventually agreed.

The Serbian army was battle-hardened: its soldiers included about 185,000 veterans of the Balkan Wars (Lyon, via the campaign article). But it was starved of material. Austro-Hungarian artillery outnumbered Serbian about two to one, and by late November the Serbs were running out of shells. Ammunition from France and Greece, together with replacements for the units, arrived in time to make the counter-offensive possible.

The Austro-Hungarian armies were better armed and supplied, but they were operating in rugged country at the end of a long supply line over bad roads, in rain and snow. Potiorek commanded the whole Balkan force, with Frank leading the 5th Army.

The battle

Retreat to the Kolubara (16–26 November). The Austro-Hungarians reached the river on 16 November and attacked on the 17th; five days of fighting in rain and snow followed around Lazarevac, just south of Belgrade. On 19 November they gained a foothold on Vrače Brdo, and on the 20th the Serbian 1st Army fell back. After a renewed attack on the 21st, the Serbs gave up Mount Maljen following three days of fighting. On 24 November Potiorek forecast victory within days and named Stjepan Sarkotić as governor of occupied Serbia. On the 25th the Austro-Hungarians took Čovka and Vrače Brdo after an artillery bombardment, and on the 26th they crossed the Kolubara near its junction with the Sava, but Serbian counterattacks reportedly inflicted about 50 per cent casualties on them. The Serbs retook Čovka and Vrače Brdo on the 27th, while the 6th Army attacked along the whole front that night.

Belgrade falls (29 November – 1 December). The Serbs evacuated Belgrade on 29–30 November and the Austro-Hungarians entered it on 1 December. Potiorek then halted the 6th Army to secure its supply lines and moved the 5th Army towards Belgrade to strike the Serbian right flank, leaving the 6th alone for a few days. Putnik, with fresh ammunition, judged the enemy overstretched.

The counter-offensive (2–10 December, CDB90 engagement 288). The Serbian armies attacked along the whole front on 2 December (the campaign article gives 3 December as Putnik's order; CDB90 starts on the 3rd), with King Peter I joining the troops. The Austro-Hungarian artillery was too far to the rear to respond. The 2nd and 3rd Armies overwhelmed the 5th Army, whose flank move came too late. On 6 December the Serbs broke the Austro-Hungarian centre and right, and a general retreat began. On the 7th the Austro-Hungarians attacked the Serbian right on Belgrade's outskirts, but on the 8th they fell back towards Užice and Valjevo; the 3rd Army broke through at Suvobor and stormed Valjevo, and Užice was retaken. A counter-offensive around Belgrade lost momentum on 9 December, and on the 10th the Serbs took the lower Drina, across which most surviving Austro-Hungarians fled.

Belgrade regained (13–16 December). On 13 December Frank told Potiorek that Belgrade could not be held. The Austro-Hungarians left on the 14th–15th, the Serbian army re-entered the capital on the 15th and held it entirely by the end of the 16th. The campaign that Potiorek had expected to end in Niš had ended with his army back across the Sava and Drina.

Aftermath

The Serbs had cleared their country. By Wikipedia's figures (Herwig), they lost 22,000 killed, 91,000 wounded and 19,000 missing or captured, while the Austro-Hungarians lost 30,000 killed, 173,000 wounded and 70,000 captured, a total of 273,000. The article's own prose says about 225,000 and cites the same source; see the flags. The Serbs captured about 200 officers, and the Austro-Hungarians had captured more than 130 guns and 70 heavy machine guns.

Strategically, the invasion achieved none of its aims: Serbia stayed in the war, Bulgaria did not join the Central Powers and Romania remained neutral. Potiorek was relieved on 22 December and replaced by Archduke Eugen; Frank was dismissed. The 5th and 6th Armies were merged into a single 5th Army of 95,000 men. Mišić was promoted to vojvoda.

The victory was costly, and the respite short. Western papers reported atrocities against civilians and at least 11 towns were abandoned. Serbia was overrun in the autumn of 1915 by a combined Austro-Hungarian, German and Bulgarian attack, when the army retreated through Albania to the Adriatic. The battle remains central to Serbian memory, and the subject of Dobrica Ćosić's novel A Time of Death.

Wargaming it

Kolubara is a battle of two halves, which suits a campaign-style game in two scenarios. The first is a withdrawal: a thin, under-supplied Serbian army must trade space for time, holding ridges such as Maljen, Vrače Brdo and Čovka long enough to keep its formations in being while its ammunition runs down. The second is a reversal in which the Serbs, resupplied, attack an overextended enemy.

The map is hilly and the weather wet, so movement and supply matter more than firepower. A useful rule is an ammunition track for each Serbian division that is deliberately sparse until a set turn, after which a resupply event lets the player attack. The Austro-Hungarian player has the opposite problem: strong artillery that falls behind in the mud, and a 5th Army that Potiorek can send towards Belgrade or keep in line.

The key decision is Potiorek's halt on 1 December and his diversion of the 5th Army. Playing that differently, or leaving the 6th Army in support, is the obvious what-if. The scale suits brigade or division units at about 1 km per hex for the two weeks of the counter-offensive, or as a map-wide operational game with corps and army boxes for the whole month. The fall and recapture of Belgrade make natural victory points.

Maps and pictures