On January 27, Field Marshal Haussen, commander of the German 3rd Army and the frontline commander in the campaign against Austria-Hungary, issued the order for an assault.
After two days of rest, the German soldiers who had endured the long march had fully regained their strength. Both physically and mentally, they were at their peak. Moreover, with the logistical units having transported a vast quantity of war supplies to the front, the moment for the decisive assault on Vienna had arrived.
"Fire!"
At precisely 8 a.m., the artillery commander gave the order to open fire. Four army groups, comprising forty infantry divisions and four armored divisions, unleashed their formidable firepower. Even the infantry divisions alone possessed staggering artillery strength—720 heavy 150mm howitzers, 1,440 light 105mm howitzers, and 2,160 field guns of 75mm caliber. In total, over 4,000 cannons thundered in unison, launching a devastating bombardment upon Vienna.
Vienna, a city steeped in history, a symbol of cultural brilliance, was of no consequence to the German military. To the artillerymen, it was merely a target—one they were tasked with reducing to rubble. And this was hardly the first time they had done so. Paris had suffered the same fate. London, too, had been pounded into ruins under the relentless German guns.
The Austro-Hungarian artillery force, though not weak, was hampered by a fatal disadvantage. The renowned Škoda heavy artillery, famed throughout the world, was produced not in Austria itself but in the Kingdom of Bohemia. The moment German forces seized Bohemia, they immediately took control of the Škoda factories. Once the war was over, the Krupp armaments empire would annex the facility, further elevating Germany's artillery manufacturing prowess.
Though the Austrian army did possess some heavy artillery, most of it had been deployed along the borders, not within Vienna itself. Heavy guns, for all their destructive power, were cumbersome and difficult to redeploy. In a retreat, they were even more of a liability. As the Austrian forces fled in disarray, they barely had time to salvage their supplies, let alone evacuate their artillery. The abandoned guns inevitably fell into German hands.
Qin Tian had long envisioned the establishment of a dedicated heavy artillery brigade within each army group, aiming to further enhance German firepower. However, the sheer weight and bulk of these weapons posed logistical challenges. Unless self-propelled models could be developed, reliance on trucks or even mule-drawn transport rendered them difficult to maneuver efficiently.
"Boom! Boom! Boom!"
Orange flames erupted from German gun barrels as shells shrieked through the air, raining destruction upon Vienna.
Like a relentless storm, the bombardment engulfed the city. Explosions rocked both the outer defensive lines and the urban strongholds—the primary targets of the German artillery.
The Austrian fortifications outside Vienna were fragile at best. Digging trenches and constructing defensive positions had never been the Austrians' forte. Their makeshift fortifications were shoddy at best, little more than token defenses. Against the ferocity of the German bombardment, such meager defenses stood no chance.
Under the relentless shelling, Austrian defenses crumbled one after another. Even those who had sought refuge in bunkers found themselves buried alive beneath collapsing earth and rubble.
The sheer intensity of the barrage shattered the morale of the defending troops. Despite Emperor Karl I's previous exhortations, nothing could prepare the Austrian soldiers for the horror unfolding before them. Seeing comrades blown apart or entombed alive tested even the most disciplined of troops. For the Austrians, whose forces were already far from elite, the psychological strain was overwhelming. Given the choice, many would have fled without hesitation.
Yet escape was hardly an option. Austrian high command had stationed punitive squads behind the lines, armed with heavy machine guns, ready to execute any who attempted to retreat without orders. Between certain death at the hands of their own and a slim chance of survival against the Germans, most soldiers had no choice but to cower in their bunkers and endure.
Moreover, the German bombardment was too intense—any attempt to flee now would likely end in immediate death. If they had to run, it would be safer to wait until the shelling ceased.
Within Vienna, the devastation was equally grim. Grand buildings that had stood for centuries crumbled beneath the relentless onslaught. Once proud monuments of history were now indistinguishable ruins, reduced to the same dust and rubble as everything else.
Fortunately, by the time the German army reached Vienna, most civilians had already fled. They knew that once war reached the city, staying behind would be tantamount to signing their own death warrants. Human life, after all, was but a fragile thing in the face of war.
Even the families of Austro-Hungarian ministers had evacuated ahead of time. Among them were the Empress and children of Emperor Karl I, who had already departed for Trieste, where they would soon board a cargo ship bound for the United States. Karl himself would follow later to reunite with them. With the civilian population gone, Vienna was now little more than a military stronghold, allowing the Germans to conduct their assault unburdened by concerns of collateral damage.
For four relentless hours, the German bombardment continued, reducing the Austrian positions outside Vienna to a wasteland. Even within the city, the destruction was staggering.
The Austrian artillery attempted a counterattack, but they were hopelessly outmatched. Outgunned and outclassed, their efforts proved futile. Losses mounted rapidly, forcing Archduke Friedrich, the Austrian commander, to order a halt to the suicidal resistance.
As the bombardment ceased, German infantry, having already eaten their midday rations and prepared for the next phase, launched their assault.
Four army groups advanced, each committing two infantry divisions and their respective armored brigades. Like tigers unleashed from the mountain, over 200,000 German troops surged forward, descending upon the Austrian lines.
For the Austrian defenders, still reeling from the bombardment, the sight of the German advance was the final blow. The black silhouettes of tanks rolling forward, the relentless tide of battle-hardened infantry—panic spread like wildfire. Even the punitive squads could not hold the line. Soldiers fled in terror, abandoning their posts in a full-scale rout.
With a single overwhelming assault, the German forces shattered the Austrian defenses outside Vienna, clearing the path for the city's inevitable fall.