Battle of Poznań ( 1945 ) The Battle of Poznań ( Battle of Posen ) during World War II in 1945 was a massive assault by the Soviet Union ' s Red Army that had as its objective the elimination of the Nazi German garrison in the stronghold city of Poznań in occupied Poland . The defeat of the German garrison required almost an entire month of painstaking reduction of fortified positions , intense urban combat , and a final assault on the city ' s citadel by the Red Army , complete with medieval touches . Background . The city of Poznań ( called " Posen " in German ) lay in the western part of Poland which had been annexed by Nazi Germany following their invasion of Poland in 1939 , and was the chief city of Reichsgau Wartheland . By 1945 , the Red Army advances on the Eastern Front had driven the Germans out of eastern Poland as far as the Vistula River . The Red Army launched the Vistula - Oder Offensive on 12 January 1945 , inflicted a huge defeat on the defending German forces , and advanced rapidly into western Poland and eastern Germany . Certain cities which lay on the path of the Soviet advance were declared by Hitler to be " Festungen " ( strongholds ) , where the garrisons were ordered to mount last - ditch stands . Hitler hoped the " Festung " cities could hold out behind Soviet lines and interfere with the movement of supplies and lines of communication . Poznań was declared a " Festung " in January 1945 . The city was defended by 40 , 000 German troops from a great variety of units including Volkssturm , Luftwaffe ground forces , police , and highly motivated officer candidates . Facing them were the experienced Guards Rifle troops of General V . I Chuikov ' s 8th Guards Army – the victors of Stalingrad . The defenders made use of some of the surviving " Festung Posen " fortifications that had been built during Prussian rule in the 19th century . The Fort Winiary citadel stood on a hill to the north of the city centre . Around the perimeter of the city were 18 massively - built forts , spaced at intervals of about 2 kilometres in a ring with a radius of about 5 kilometres . General Chuikov described the forts as . . . underground structures each with several storeys , the whole projecting above the surrounding terrain . Only a mound was visible above ground - - the layer of earth covering the rest . Each fort was ringed by a ditch ten metres wide and eight metres deep , with walls revetted with brickwork . Across the ditch was a bridge , leading to one of the upper storeys . Among the forts , to the rear , there were one - storey brick bunkers . These were clad in concrete almost a full metre thick , and were used as stores . The upper works of the forts were sufficiently strong to provide reliable protection against heavy artillery fire . . . . the enemy would be able to direct fire of all kinds against us both on the approaches to the forts and within them , on the rampart . The embrasure s were such that flanking fire from rifles and machine - guns could be directed from them . The city encircled . Poznań lay on the main route between Warsaw and Berlin , and in German hands , was a serious obstacle to Soviet resupply efforts between Poznań and Berlin . Thus , the Red Army had to clear the city of German troops before the final assaults designed to capture Berlin and end the war could begin . On 21 January 1945 the Soviet 1st Guards Tank Army forced a crossing of the Warta River north of the city , but by 24 January these bridgeheads had been abandoned in favor of better bridgeheads south of Poznań . Meanwhile , Red Army tank units had swept north and south of the city , capturing hundreds of German aircraft in the process . Moving further west , the Soviet tank units left the capture of the city to other Red Army forces . By 25 January , the Soviet 8th Guards Army had arrived and began a systematic reduction of the fortress . The following day , two of Poznań ' s forts in the south fell to a hasty assault conducted by the 27th and 74th Guards Rifle Divisions . This initial success allowed Chuikov ' s troops to penetrate the ring of forts and attack other forts from inside the city . On 28 January , the German high command relieved " Generalmajor " Ernst Mattern as the fortress commander and replaced him with a dedicated Nazi , " Generalmajor " Ernst Gonell . Gonell imposed draconian discipline on the German garrison . In some instances , German troops attempting to surrender were shot by their own side . Ultimately , the reduction of " Festung Posen " consumed the efforts of four divisions from Chuikov ' s army and two divisions of Colonel - General V . Ia . Kolpakchi ' s 69th Army . The 117th and 312th Rifle Divisions of the 91st Rifle Corps ( 69th Army ) were deployed on the east side of the city . To the north , the 39th Guards Rifle Division of Chuikov ' s 28th Guards Rifle Corps , and to the south , Chuikov ' s 29th Guards Rifle Corps composed of the 27th , 74th , and 82nd Guards Rifle Divisions were arrayed against the " Festung " . By the southwestern suburb of Junikowo , the 11th Guards Tank Corps took up positions to block any German attempt at retreat . The capture of Poznań . In bitter combat that saw the outlying forts reduced and city blocks seized , the Soviets succeeded in pushing the German defenders towards the city center and the citadel . By the beginning of February 1945 , most of the city had been captured , and by 12 February , the Germans held only the imposing citadel . " Generalmajor " Gonell had previously believed that other German forces would attack and relieve his besieged forces , but by 15 February came to the realization that this was not going to happen . Incensed , he ordered his troops that were east of the Warta River to attempt to break out , and some 2 , 000 German soldiers managed to infiltrate the Red Army lines and head west on the following night . Arrayed against the citadel was the 29th Guards Rifle Corps , with the 27th Guards Rifle Division on the north , the 82nd Guards Rifle Division on the southwest , and the 74th Guards Rifle Division on the southeast . The final Soviet assault on the citadel started on 18 February . Before the Red Army troops lay a deep ditch matched by a steep rampart on the far side . In an odd echo of medieval warfare , the Soviet forces used ladders to cross this obstacle , but found themselves swept by fire from the citadel ' s redoubt s . These redoubts took the better part of three days to neutralize ; one silenced by flamethrowers and explosives , the other ' s line of fire blocked by debris thrown in front of the firing ports by exasperated Soviet troops . Having built an assault bridge , Red Army tanks and assault guns crossed into the main grounds of the citadel early on 22 February , commencing the final struggle for the old fortress . At this point , " Generalmajor " Gonell gave his troops permission to attempt to escape , but it was too late . Gonell refused to be captured and committed suicide by lying down on a flag and shooting himself in the head . That evening , " Generalmajor " Mattern , once again in charge of the German forces , surrendered the remaining 12 , 000 German soldiers to General Chuikov . Aftermath . The Germans held out in Poznań for almost a month . Doubtlessly , their possession of the city complicated Soviet resupply efforts , but other influences had also convinced the Stavka to pause the Red Army advance at the Oder River instead of attempting to push on to Berlin in February 1945 . The battle left over half ( 90 % in the city center ) of Poznań severely damaged by artillery fire and the effects of infantry combat in the city blocks . The battle definitively reduced the old Prussian fortress system which today stands mostly as monuments to an earlier military era . Finally , the outcome of the battle simplified Soviet resupply efforts between Warsaw and the Oder River . Over 5 , 000 German troopers who fell in the battle are buried at Milostowo cemetery . The Soviets are estimated to have lost over 12 , 000 men by the battle ' s midpoint around 3 February 1945 . Today , the Poznań Citadel site is a large park , in which are situated the remains of some of the fortifications , a memorial to the Red Army , military cemeteries , and a military museum containing exhibits relating to the 1945 battle .