Vienna Offensive The Vienna Offensive was launched by the Soviet 3rd Ukrainian Front in order to capture Vienna in German - occupied Austria . The offensive lasted from 2 – 13 April 1945 . The city of Vienna was surrounded and under siege for most of the offensive . Background . Joseph Stalin reached an agreement with the Western Allies prior to April 1945 concerning the relative postwar political influence of each party in much of Eastern and Central Europe ; however , these agreements said virtually nothing about the fate of Austria , then officially considered to be merely the Ostmark area of Greater Germany after the Anschluss . As a result , the victory of a Soviet offensive toward Austria and the liberation ( by the Red Army ) of a large part of this country would be very beneficial for subsequent postwar negotiations with the Western Allies . After the failure of Operation Spring Awakening ( " Unternehmen Frühlingserwachen " ) , Sepp Dietrich ' s 6th SS Panzer Army retreated in stages to the Vienna area . The Germans desperately prepared defensive positions in an attempt to guard the city against the rapidly - arriving Soviets . In spring 1945 , the advance of Soviet General Fyodor Tolbukhin ' s 3rd Ukrainian Front through western Hungary gathered momentum on both sides of the Danube . On 30 March , the advancing Soviets forced the Hron River , forced the Nitra River , and after they took Sopron and Nagykanizsa ; crossed the border between Hungary and Austria . Tolbukhin was now ready to advance into Austria and take Vienna . The battle . On 2 April , Vienna Radio denied that the Austrian capital had been declared an open city . On the same day , Soviet troops approached Vienna from the south after they overran Wiener Neustadt , Eisenstadt , Neunkirchen and Gloggnitz . Baden and Bratislava were overrun on 4 April . After arriving in the Vienna area , the armies of the Soviet 3rd Ukrainian Front surrounded , besieged , and attacked the city . Involved in this action were the Soviet 4th Guards Army , the Soviet 6th Guards Tank Army , the Soviet 9th Guards Army , and the Soviet 46th Army . The " O - 5 Resistance Group , " Austrians led by Carl Szokoll wanting to spare Vienna destruction , actively attempted to sabotage the German defenses and to aid the entry of the Red Army . The only major German force facing the Soviet attackers was the German II SS Panzer Corps of the 6th SS Panzer Army , along with ad hoc forces made up of garrison and anti - aircraft units . Declared a defensive region , Vienna ' s defense was commanded by General Rudolf von Bünau , with the II SS Panzer Corps units under the command of SS General Wilhelm Bittrich . The battle for the Austrian capital was characterized in some cases by fierce urban combat , but there were also parts of the city the Soviets advanced into with little opposition . Defending in the Prater Park was the 6th Panzer Division , along the south side of the city were the 2nd and 3rd SS Panzer Divisions , and in the north was the " Führer " - Grenadier Division . The Soviets assaulted into Vienna ' s eastern and southern suburbs with the 4th Guards Army and part of the 9th Guards Army . The German defenders kept the Soviets out of the city ’ s southern suburbs until 7 April . However , after successfully achieving several footholds in the southern suburbs , the Soviets then moved into the western suburbs of the city on 8 April with the 6th Guards Tank Army and the bulk of the 9th Guards Army . The western suburbs were especially important to the Soviets because they included Vienna ' s main railway station . The Soviet success in the western suburbs was followed quickly by infiltration of the eastern and northern suburbs later the same day . North of the Danube River , the 46th Army pushed westward through Vienna ' s northern suburbs . Central Vienna was now cut off from the rest of Austria . By 9 April , the Soviet troops began to infiltrate the center of the city , but the street fighting continued for several days more . On the night of 11 April , the 4th Guards Army stormed the Danube canals , with the 20th Guards Rifle Corps and 1st Mechanized Corps moving on the " Reichsbrücke " Bridge . In a " coup de main " on 13 April , the Danube Flotilla landed troops of the 80th Guards Rifle Division and 7th Guards Airborne Division on both sides of the bridge , cutting demolition cables and securing the bridge . However , other important bridges were destroyed . Vienna finally fell when the last defenders in the city surrendered on the same day . Bittrich ' s II SS Panzer Corps , however , pulled out to the west on the evening of 13 April to avoid encirclement . The same day , the 46th Army took Essling and the Danube Flotilla landed naval infantry up the river by Klosterneuburg . While the street fighting was still intensifying in the southern and western suburbs of Vienna on 8 April , other troops of the 3rd Ukrainian Front by - passed Vienna altogether and advanced on Linz and Graz . Aftermath . By 15 April , armies of the Soviet 3rd Ukrainian Front pushed even further into Austria . The completely exhausted remnants of what had been the 6th SS Panzer Army were forced to flee to the area between Vienna and Linz . Just behind the retreating Germans were elements of the Soviet 9th Guards Army and the Soviet 46th Army . The 26th Army and 27th Armies advanced towards the area north of Graz just behind the retreating 6th Army . The 57th Army and the Bulgarian 1st Army advanced towards the area south of Graz ( near Maribor ) just behind the retreating 2nd Panzer Army . None of these German armies was in any shape to do more than temporarily stall the advancing Soviet forces . Some of Vienna ' s finest buildings lay in ruins after the battle . There was no water , electricity , or gas — and bands of people , both foreigners and Austrians , plundered and assaulted the hapless residents in the absence of a police force . While the Soviet assault forces generally behaved well , the second wave of Soviet troops to arrive in the city were badly disciplined , looting and raping in a several - week orgy of violence that has been compared to the worst aspects of the Thirty Years War . Like Bittrich , General von Bünau left Vienna before it fell to avoid capture by the Soviets . From 16 April until the war ' s end , he led " Generalkommando von Bünau " , surrendering to the Americans on VE Day . von Bünau was held as a POW until April 1947 . Bittrich also surrendered to U . S . forces and was held as a prisoner by the Allies until 1954 . Fyodor Tolbukhin went on to command the Soviet Southern Group of Forces and the Transcaucasian Military District prior to his untimely death in 1949 , reportedly from heart problems . Austrian politician Karl Renner astutely set up a Provisional Government in Vienna sometime in April with the tacit approval of the victorious Soviet forces , and declared Austria ' s secession from the Third Reich . Final orders of battle ( after the Vienna Offensive ) . German and German allied forces . On 30 April , the following order of battle was recorded by the German Army High Command ( " Oberkommando der Wehrmacht " , or OKW ) . From 20 April - 2 May , OKW moved from Zossen ( near Berlin ) to Mürwik ( part of Flensburg in north Germany , near Denmark ) . This order of battle shows what remained " on paper " of the German armies that fought in Hungary and Austria . Soviet and Soviet allied forces . The order of battle for the 3rd Ukrainian Front during the same period was :