[This is the beginning of a new blog series, 100 Years Ago, I’ll be posting to commemorate the centenary of the First World War.]
Exactly a century ago today, on 19 August 1914, Austria-Hungary suffered a shocking battlefield defeat at the hands of Serbia, delivering the Allies their first victory of the Great War. This unexpected defeat occurred in the mountains of northwest Serbia, with Austro-Hungarians forces sent back into Bosnia in a ragtag state after suffering a sharp local setback that quickly unraveled the entire Habsburg invasion of Serbia.
Vienna invaded “Dog Serbia” in mid-August to avenge the murder of Archduke Franz Ferdinand by Belgrade-backed assassins in Sarajevo on 28 June. Although Austro-Hungarian intelligence did not have a complete picture of the background to the assassination — there remain unanswered questions even today — they knew enough that it was time to settle accounts with troublesome little Serbia, which had been an ever sharper thorn in the side of the Dual Monarchy for a decade.
Throughout July, exasperated Austro-Hungarian generals sent letter after letter, pleading for action. Many senior officers worried that diplomats would find a peaceful solution to the crisis that engulfed Europe after the assassination of the heir to the Habsburg throne. Typical was General Michael von Appel, commander of the Austro-Hungarian XV Corps in Sarajevo, who expressed his “feverish longing” for war “to finish off those murder-boys (Mordbuben)” in Belgrade: “God grant us only that we remain steadfast…oh that we could march forth, we’re only lacking faith…just let it go (nur los lassen) – we’ll take care of the rest.”
No Habsburg general was chomping harder at the bit to crush Serbia than Oskar Potiorek (left), Bosnia’s governor-general, on whose watch the murder of Franz Ferdinand had taken place. It happened before his very eyes, as he was sharing the limousine with the ill-fated archduke and his equally ill-fated wife Sophie when they were gunned down by Gavrilo Princip. An accomplished careerist, Potiorek was desperate for a war to avenge his failure to protect the archduke and settle scores with the hated Serbs. Regrettably for Austria-Hungary, Potiorek looked more impressive on paper than in reality. He had never seen battle and, while he excelled at gaining powerful connections at the Viennese court, his military skills were questionable, and his actual time commanding troops had been limited. To make matters worse, Potiorek lived hermit-like in his Sarajevo palace, apart from his troops and even most of his generals, taking scant interest in his command. Appel considered his superior to be “no judge of character, a resident of Mars,” while another exasperated general compared the isolated Potiorek to the Dalai Lama!
Once the war he wanted came, with Austro-Hungarian mobilization on 1 August, Potiorek implemented what turned out to be a deeply flawed war plan. Although the traditional invasion route into Serbia, which had been executed several times by Habsburg forces over the centuries, involved a drive on the capital Belgrade, on the border with Hungary, Potiorek instead placed the bulk of his forces, the 5th and 6th Armies, on the Drina river (see map), where they would attack into mountainous northwestern Serbia. There would be a supporting attack to the north, around the city of Šabac, by the 2nd Army, but that would be brief as, due to a desperate shortage of troops, that army would need to leave Serbia by 18 August to reach Galicia in time to take on the Russians.
While Potiorek cannot be blamed for the fact that the Austro-Hungarian Army lacked the men and weapons to wage a two-front war with any hope of success — that was the fault of the General Staff chief, General Franz Conrad von Hötzendorf, who refused to craft an overall war plan that matched the Dual Monarchy’s actual military potential in 1914 — he bears full responsibility for the fact that the invasion of Serbia that August took little account of the difficult terrain or Serbia’s lack of decent roads. Neither were the 5th and 6th Armies deployed close enough together to support each other in the offensive. It was a recipe for a slow slog across the Drina and potential disaster.
On paper, the armies were roughly evenly matched, with Potiorek’s invasion force possessing 282.000 riflemen, 10,000 cavalry, and 744 guns, against Serbian strengths of 264,000 riflemen, 11,000 cavalry, and 828 guns. However, these figures are deceptive. First, the departure of the 2nd Army beginning on 18 August would deprive Potiorek of one-third of his force. In addition, Serbia boasted tens of thousands of irregulars, guerrillas known as komitadji, who would support the main army with constant harassment of the invader; for Habsburg forces they proved more than nuisance. Above all, while Potorek’s army was untried — as Austro-Hungarian forces had last seen battle in 1882, suppressing a revolt in Bosnia-Hercegovina, no officer below the rank of general had ever heard a shot fired in anger — Serbia’s army boasted extensive combat experience, having been recently blooded in the fierce Balkan Wars of 1912-1913.
Serbia’s soldiers were motivated to defend their homeland, and they knew the terrain intimately (a prewar exercise at Serbia’s war college had posited an Austro-Hungarian invasion across the Drina), helped by the fact that Colonel Alfred Redl, a senior Habsburg intelligence officer who was unmasked as a traitor just a year before the Great War, had passed top secret war plans to the Russians, who shared the relevant ones with their Serbian allies. No less, Serbia’s army was in some ways better equipped than the invader. While the forces were comparable in small arms, Serbia possessed an advantage in artillery, which was a particular Austro-Hungarian weak-point due to chronic underfunding of the military. In most classes of field guns, Serbia possessed more modern and longer-ranged artillery than Habsburg forces did.
Nevertheless, Potiorek was brimming with confidence when his army crossed the Drina on 12 August. Faith in an easy victory over the despised Serbs, mere Balkan peasants, was widespread in Vienna. Many officers predicted “a brief autumn stroll” (einen kleinen Herbstspaziergang) through Serbia, while the chief of the Balkans operational group on the General Staff assessed, “we’ll be able to chase off the Serbs with a wet rag.” This was not a failure of intelligence. In the years before the war, Austro-Hungarian military intelligence, the quaintly named Evidenzbureau, had a good understanding of Serbia’s military potential. Its 1913 assessment of the Serbian Army was remarkably accurate in its depiction of Belgrade’s forces, including its powerful artillery; it was anything but dismissive of the little country’s military. Similarly, the June 1913 report by Major Otto Gellinek, the Habsburg military attaché in Belgrade, concluded that Serbia’s military had a great deal of recent combat experience and modern weaponry, and deserved to be taken seriously, especially when fighting in defense of its own soil. None of this made much of an impression on Potiorek, or most Habsburg generals, who ignored intelligence that they did not wish to see.
In most places the Drina was shallow enough for the infantry to ford it, though artillery and supply trains needed bridges. Austro-Hungarian forces encountered only sporadic resistance at the river’s edge — it was clear the Serbs were holding back and planning to defend inland — but the terrain made the advance into enemy territory slow and arduous. The main drive was made by the 5th Army, whose combat units were inside Serbia by late on 13 August, headed for the city of Valjevo. But between them were fifty miles of hills and mountains with few decent roads, and thousands of komitadji. From the moment they crossed the Drina, Habsburg forces were harassed by Serbian irregulars. They were a menace to Austro-Hungarian supply units especially, with the result that logistics broke down almost immediately once Potiorek’s forces entered Serbia. The 5th Army’s lead division in the advance, the 21st Infantry, received some water but no food on 13 August; some food reached its infantry on 14 August but no water; by 15 August only a single battalion had established functioning field kitchens and almost no water made it to the infantry; on 16 August neither food nor water reached the division’s combat units, and things did not improve the following day. For the 21st Division, marching up hills in hot summer temperatures, crisis was reached almost immediately, not least because it belonged to the Landwehr, roughly equivalent to the U.S. National Guard, not the regular army, and its thirty-something reservists were in no shape for the hard slogging up Serbian hills under the beating August sun.
Habsburg forces had little idea where the enemy’s main forces were, and units of Prague’s VIII Corps advanced blindly through forests and over hills: they would find the Serbs by meeting them in battle. It was the hard luck of the unready 21st Division to get the assignment of taking Cer Mountain, a thickly wooded 2,300-foot-high ridge that overlooked the valleys of the Drina and Jadar rivers and stood as the major obstacle in the path of the 5th Army’s march on Valjevo. On the morning of 14 August, the mostly Czech troops of the 21st Division began their hike up Cer, a rugged and roadless plateau nearly twelve miles long and four miles wide, dominated by undulating hills and ridges, with vast cornfields beyond.
By midday, many Habsburg infantry, lacking water, had collapsed from heat exhaustion, and the 21st Division’s march up Cer was slow and vulnerable, as most of its artillery was left behind, unable to make it up narrow mountain tracks. Rear-area units and infantry alike suffered regular sniping from komitadji, but there was no sign of the main Serbian force as the division advanced ponderously. By the morning of 15 August, the 21st Division’s forward elements were ready to climb Hill 630, the highest of the peaks on the Cer plateau, located at its eastern edge, undeterred by short, sharp attacks by guerrillas. By the late afternoon the division’s lead battalion, from the 28th Landwehr Regiment, had reached the summit of Hill 630. After a brief rest the 21st Division’s commander, General Arthur Przyborski, wanted the tired infantry to get on their feet and advance farther but a rainstorm caused a delay, and soon the order came for the troops to hunker down for the night. Given their exhaustion, there was no other choice. Sentries were posted and the Habsburg infantry, strung out all along the eastern edge of the Cer plateau, went to sleep, without food or water.
The first soldiers of the 21st Division to die in the battle for Cer, some killed in their sleep, never knew what hit them when Serbian forces opened fire at close range at 1 a.m. on 16 August. Radomir Putnik, Serbia’s generalissimo, a hard veteran of many wars, was a skilled tactician who devised a cunning plan to turn back the Austro-Hungarian invasion, waiting for Habsburg forces to advance inland and become spread out to strike back with great force. Vienna might have been spared Putnik’s plan as the sixty-seven year old general was on Habsburg soil when the war broke out, taking the cure at a Bohemian spa. Putnik was briefly interned, but was soon released as a soldierly gesture by Emperor Franz Joseph, a stickler of the old school who thought it dishonorable to detain Putnik under such circumstances, thus allowing him to return home to defeat the Habsburg Army.
By mid-August, Putnik was ready to counterattack, with his 2nd Army, led by General Stepa Stepanović, a fierce warrior with extensive battle experience, quietly approaching the Austro-Hungarians around Cer. Two infantry regiments, more than 6,000 riflemen, advanced quietly in the darkness through cornfields and fell upon the lead elements of the 21st Landwehr Division without warning as they slept. Chaos accompanied the Serbian bayonet charge, and in the darkness Austro-Hungarian officers and NCOs tried to rally their groggy soldiers; many were cut down before they could form any coherent defense. Serbian infantry kept coming, as reinforcements surged from the corn, and Habsburg platoons, then companies were overrun and melted away in the darkness. Habsburg officers fell quickly, including Colonel Joseph Fiedler, commander of the 28th Landwehr Regiment, who died while trying to form his sleepy soldiers into a defensive line.
Before long the 21st Division’s command staff was in the thick of the melée. Rifle in hand, General Przyborski rallied his startled soldiers as Serbian bayonet attacks grew closer. At one point in the desperate fight, Przyborski had only twenty soldiers around him, but the position held, although the general counted among those wounded. Several hundred yards west of the divisional command post, the 6th Landwehr Regiment was fighting back with bayonets and even hand-to-hand, as the enemy had used the darkness to infiltrate between Habsburg companies. Adding to the confusion, the Serbs employed Austro-Hungarian bugle calls for deception purposes. The regiment’s 3rd Battalion nearly buckled under the strain, but the 1st Battalion, roused from sleep, arrived in time to prevent a Serbian breakthrough. Yet losses were steep, as Serbian rifle and machine gun fire was concentrated and accurate. This meeting engagement, which went on bloodily until dawn, was more a series of firefights than a coherent battle, and casualties on both sides proved steep. The division’s 41st Brigade formed a lager around its commander and his staff, which withstood repeated Serbian bayonet assaults.
By dawn on 16 August both sides were exhausted, so Stepanović committed a third infantry regiment to the fight and moved his artillery, which had been delayed by muddy roads, into position. Two batteries deployed forward, close to Habsburg positions, firing over open sights and inflicting heavy losses, their shells tearing frightful gaps in the closely deployed defenders. It was a one-sided artillery duel, as Austro-Hungarian gunnery was overwhelmed. Most batteries had been kept too far back, or were under attack themselves as Serbian infantry and irregulars kept advancing. The 21st Division’s guns were mostly out of range, but the neighboring 9th Division’s batteries offered some fire support. Yet Habsburg infantry-artillery cooperation was haphazard at best, and a high level of confusion paralyzed coordination; in the chaos, many battalion commanders simply did not know where their companies were. For several hours that morning, the 21st Division ceased to function much above the company level. Przyborski’s two brigadiers did not know where he was, or even if their commanding general was alive.
By late morning, positions had stabilized as exhaustion brought the encounter battle to a close. Word travelled up the Habsburg chain of command about the extent of the 21st Division’s losses, particularly the shattered 28th Regiment. 5th Army command, hearing ominous initial reports and fearing a debacle which threatened to unravel the whole front, wanted the division to withdraw. Yet while the 21st Division was in chaos, the neighboring 9th Division was holding fast. The Serbs had taken grave losses too: its lead division in the attack lost forty-seven officers and nearly 3,000 men, and in its 6th Regiment all four battalion commanders and thirteen of sixteen company commanders were dead or wounded. Potiorek, too, worried about the whole Drina line collapsing, so on the afternoon of 16 August the 21st Division began a slow retreat back to the river. Serbian King Peter watched the day’s happy events from a nearby hilltop.
The retreat was disorganized, in part because komitadji and Serbian cavalry harrassed Habsburg forces every mile along the route back to the Drina. Throughout 17 August, the 21st Division repelled enemy attacks great and small, while some units began to fall apart under the pressure; disorder among supply trains was universal, and logistics were in free fall. As the Habsburg 6th Army was too far to the south to support the ailing 5th Army, there was no choice but to declare a general retreat from Serbia. There was little to celebrate on 18 August, Emperor Franz Joseph’s birthday, not least because that day the 2nd Army began to disengage the Serbs in preparation for its rail journey to fight the Russians in Galicia.
Knowing the Austro-Hungarians were retreating, Stepanović pushed harder. Habsburg troops were tired, hungry, and thirsty, as the struggle for supplies was going as badly as the fight with the Serbs, but the retreat was orderly at first, considering the difficult terrain. Yet chaos spread, unit to unit. Afraid of being massacred by komitadji – rumors were rife of knife-wielding women hacking apart Habsburg wounded – the jumpy troops stayed alert and close together. By the time the 21st Division began reaching the safety of the left bank of the Drina in Bosnia late on 19 August, battalions were showing serious weariness and morale was flagging. Some units simply fell apart as they neared the Drina. Egon Erwin Kisch, a noted Prague journalist — he had broken the salacious story of the Redl spy scandal a year before — witnessed the retreat as a reserve NCO in a Czech regiment of VIII Corps, and he was shocked by how rapidly things had gone wrong: “a boisterous horde fleeing in thoughtless panic towards the border,” his shattered battalion led by a mere subaltern, its companies led by sergeants. “The army is defeated, on a lawless, wild, hasty retreat,” he lamented to his diary.
The 21st Landwehr Division had been badly bloodied in the short but intense battle for Cer. It lost one-third of its infantry, about 4,000 men, as casualties. The 28th Regiment, which was shattered on the slopes of Cer, lost 1,700 men, over half its strength. Losses among infantry officers were “nearly colossal,” reported 5th Army command. The 6th Landwehr Regiment, which fought hard, preventing the 21st Division’s defeat from becoming a total rout, lost its colonel commanding, four majors, fifteen captains, and thirty-three subalterns, in all over two-thirds of its commissioned ranks.
By 24 August, no Austro-Hungarian troops remained on Serbian soil. The “brief autumn stroll” had ended in disaster. Vienna lost more than 23,000 soldiers killed, wounded, and missing in the brief campaign, winning nothing but an appreciation for Serbian tenacity and martial skill. Over four thousand Habsburg prisoners of war, forty-six artillery pieces, and thirty machine guns had been left in Serbian hands. Serbian casualties of 16,000 were considerable, but there was no mistaking that this had been an historic defeat for the House of Habsburg. The loss of prestige for the army and the monarchy was vast, and its diplomatic implications in the Balkans were frightening for Vienna.
For Oskar Potiorek, this was a personal disaster too. Furious at the ignominious collapse of his invasion, he sought a scapegoat, finding one in the battered 21st Division. He put the beaten division under special martial law and sought “cowards” to put up on charges of desertion, officers included. Fortunately cooler heads prevailed in Sarajevo before weary Habsburg soldiers faced the firing squad, but Potiorek shifted blame to the mostly Czech soldiers who fought and died at Cer, rather than accept any responsibility himself for flawed plans and worse execution. Austria-Hungary had sent unprepared forces into battle, lacking supplies, against a crafty and motivated enemy in easily defensible terrain. The outcome could have been predicted but, in a fit of aggression and wishful thinking, was not.
Cer, though rarely heard of outside the Balkans, thus became the first Allied victory of the Great War, as well as the first of many Habsburg defeats. While Austria-Hungary and its polyglot army would hold on to the bitter end in autumn 1918, losing seven of the eight million soldiers it mobilized for the war as a casualty of some sort, the highest loss rate of any belligerent in the war, the opening defeat at Cer was a black mark on Habsburg arms that endured. The shame of sudden defeat at the hands of little Serbia was a blow from which Viennese prestige — and Potiorek’s too — never fully recovered.
[Note: The full story of the Cer disaster is told in my forthcoming book Fall of the Double Eagle: The Battle for Galicia and the Demise of Austria-Hungary.]