Battle of Wizna The Battle of Wizna was fought between September 7 and September 10 , 1939 , between the forces of Poland and Germany during the initial stages of Invasion of Poland . According to latest sources under 720 Poles defended a fortified line for three days against more than 40 , 000 Germans . Although defeat was inevitable , the Polish defence stalled the attacking forces for three days and postponed the encirclement of Independent Operational Group Narew fighting nearby . Eventually the tanks broke through the Polish line and eliminated all the bunkers one by one . The last bunker surrendered around midday on September 10 . Because the battle consisted of a small force holding a piece of fortified territory against a vastly larger invasion for three days at great cost before being annihilated , Wizna is sometimes referred to as " Polish Thermopylae " in Polish culture . One of the symbols of the battle is Captain Władysław Raginis , the commanding officer of the Polish force , who swore to hold his position as long as he is alive . When the last two bunkers under his command ran out of ammunition , he ordered his men to surrender their arms and committed suicide . History . Background . Before the war , the area of the village of Wizna was prepared as a fortified line of defence . It was to shield the Polish positions further to the south and guard the crossing of the Narew and Biebrza rivers . The long line of Polish defences stretched between the villages of Kołodzieje and Grądy - Woniecko , with Wizna in the centre . The line ran some from the border with East Prussia , along an elevated banks of Narew and Biebrza rivers . Units defending the line were subordinate to the Polish Independent Operational Group Narew shielding Łomża and providing defence of the northern approach to Warsaw . The Wizna fortified area was one of the most important nodes in Northern Poland , providing cover of both the river crossings , and the roads Łomża – Białystok and roads towards Brześć Litewski on the rear of Polish forces . The first construction works were started in June 1939 , only two months before the outbreak of World War II . The spot was chosen carefully : most of the concrete bunker s were built on hills overlooking a swampy Narew River valley . They could be reached either through direct assault through the swamps or by attack along the causeway leading from the bridge in Wizna . Before September 1 , 1939 , only 16 bunkers were built out of 60 planned . Six of them were heavy concrete bunkers with reinforced steel cupolas ( 8 tons of weight ) , armed with machine guns and anti - tank artillery . Additional two were light concrete bunkers , armed with machine guns only . The remaining eight were ad - hoc machine gun pillbox es , protected mostly by sandbags and earthworks . Four additional heavy bunkers were under construction at the moment World War II started . In addition , the area was reinforced with trench es , anti - tank and anti - personnel obstacles , barbed wire lines and land mine s . There were also plans of breaking the dams on the Biebrza and Narew rivers to flood the area , but the summer of 1939 was one of the driest seasons in Polish history and the water level was too low . Although not all bunkers were ready by the beginning of the war , the Polish lines of defences were well - prepared . The walls of an average bunker , 1 . 5 metres thick and reinforced with 20 - centimetre - thick steel plates , could withstand a direct hit from even the heaviest guns available to the Wehrmacht at the time . The bunkers were situated on hills which gave good visibility of all the advancing forces . Opposing forces . The Polish defensive line was initially manned by a single battalion from the 71st Infantry Regiment , commanded by Mjr . Jakub Fober . However , shortly before the outbreak of World War II it was reinforced with a machine gun company from Osowiec Fortress under Capt . Władysław Raginis , as well as numerous smaller detachments from a variety of units . On September 2 , 1939 , the III / 71 battalion departed for Osowiec and Mjr . Fober passed command over Wizna to Raginis and his men . Altogether , the Polish defensive position was manned by 720 men : 20 officers and 700 NCOs and privates . However , some sources claim that the Polish unit was even weaker and was no more than 360 men strong . Although the Polish units were almost entirely composed of conscripts mobilised in August 1939 rather than professional soldiers , their morale was very high . After the war Guderian had trouble explaining why his Corps was stopped by such a small force . In his memoirs he attributes the delay to his officers " having trouble building bridges across the rivers " . During the Nuremberg Trials he remarked that Wizna was " well - defended by a local officer school " . Before the battle . On September 1 , 1939 , the Polish Defensive War and World War II started . The German 3rd Army was to advance from East Prussia towards Warsaw , directly through the positions of Polish Narew Corps . On September 2 Captain Władysław Raginis was named the commander of the Wizna area . As his command post he chose the " GG - 126 " bunker near the village of Góra Strękowa . The bunker was located on a hill in the exact centre of the Polish lines . His forces numbered approximately 700 soldiers and NCOs and 20 officers armed with 6 pieces of artillery ( 75mm ) , 24 HMG s , 18 machine gun s and two Kb ppanc wz . 35 anti - tank rifle s . After initial clashes at the border , the Podlaska Cavalry Brigade operating in the area , during the night of 3 / 4 September was ordered to withdraw and on September 5 it left the area and marched toward Mały Płock to cross the river Narew . On September 3 Polish positions were spotted from the air and strafed with machine gun fire from enemy fighters . On September 7 , 1939 , the reconnaissance units of the 10th Panzer Division of general Nikolaus von Falkenhorst captured the village of Wizna . Polish mounted reconnaissance squads abandoned the village after a short fight and retreated to the southern bank of Narew . When German tanks tried to cross the bridge , it was blown up by Polish engineers . After dark , patrols of German infantry crossed the river and advanced towards Giełczyn , but were repelled with heavy casualties . On September 8 general Heinz Guderian , commander of the XIX Panzer Corps , was ordered to advance through Wizna towards Brześć . By early morning of September 9 his units reached the Wizna area and were joined with 10th Panzer Division and " Lötzen " Brigade already present in the area . His forces numbered some 1 200 officers and 41 000 soldiers and NCOs , equipped with over 350 tank s , 108 howitzer s , 58 pieces of artillery , 195 anti - tank guns , 108 mortar s , 188 grenade launchers , 288 heavy machine gun s and 689 machine gun s . Altogether , his forces were some 60 times stronger than the Polish defenders . Defence of Wizna . In the early morning German planes dropped leaflets that urged the Poles to surrender and claimed that most of Poland was already in German hands , and that further resistance was futile . In order to strengthen the morale of his troops Władysław Raginis and Lt . Brykalski swore that they would not leave their post alive and that resistance would continue . Soon after that a German artillery barrage and aerial bombardment started . The Polish artillery was much weaker and was soon forced to retreat towards Białystok . After preparation , the Germans attacked the northern flank of the Polish forces . Two platoons defending several bunkers located to the north of Narew were attacked from three sides by German tanks and infantry . Initially the losses among German infantry were high , but after heavy artillery fire the commander of the Giełczyn area , First Lieutenant Kiewlicz , was ordered to burn the wooden bridge over Narew and withdraw to Białystok . The remnants of his forces broke through the German encirclement and reached Białystok , where they joined the forces of general Franciszek Kleeberg . At the same time an assault on the southern part of Polish fortifications became a stalemate . The Polish bunkers lacked adequate anti - tank armament , but were able to rake the German infantry with machine gun fire . However , at 6 o ' clock in the evening the Polish infantry was forced to abandon the trenches and field fortifications and retreat into the bunkers . The German tanks could finally cross the Polish lines and advance towards Tykocin and Zambrów . However , the German infantry was still under heavy fire and was pinned down in the swampy fields in front of the Polish bunkers . Although Raginis was subordinate to Lt . Col . Tadeusz Tabaczyński , commander of the Osowiec fortified area located some 30 kilometres to the north , he could not expect any reinforcements . On September 8 the Marshal of Poland , Edward Śmigły - Rydz , ordered the 135th Infantry Regiment that constituted the reserves of both Osowiec and Wizna , to be withdrawn to Warsaw . When the order was withdrawn and the unit returned to Osowiec , it was already too late to help the isolated Poles at Wizna . Heavy fighting for each of the now isolated bunkers continued . Several assaults were repelled during the night and in the early morning of September 10 . At approximately 11 o ' clock German engineers , with the help of tanks and artillery , finally managed to destroy all but two of the Polish bunkers . Both of them were located in the centre of Strękowa Góra and continued fighting despite having much of the crew wounded or incapacitated and most of their machine guns destroyed . After the war , the Poles insisted that Heinz Guderian , in an attempt to end the Polish resistance , threatened the Polish commander that he would shoot the POWs if the remaining forces did not surrender . The resistance however continued for another hour , when a German envoy arrived carrying a flag of truce and proposed a cease fire . It lasted until approximately 13 : 30 pm . Raginis , realising that all of his men were wounded and his ammunition was almost depleted , ordered his men to surrender their arms to the Germans . He himself - seriously injured at the time - refused to surrender and committed suicide by throwing himself on a grenade . Aftermath . After the Polish resistance ended , the XIX Panzer Corps advanced towards Wysokie Mazowieckie and Zambrów , where it fought the unsuccessful Battle of Zambrów against the Polish 18th Infantry Division , finally encircling and destroying the Polish division during the Battle of Andrzejewo . Later it advanced further southwards and took part in the Battle of Brześć . Although all the bunkers were destroyed and the Polish resistance was finally broken , the fortified area of Wizna managed to halt the German advance for three days . The heroic struggle against overwhelming odds is nowadays one of the symbols of the Polish Defensive War of 1939 and is a part of Polish popular culture . Casualties . Exact Polish losses are unknown , mostly because very little is known of the soldiers that were taken as prisoners of war by the Germans . Out of 720 Polish soldiers only approximately 70 survived . Some successfully withdrew and reached the Polish lines , others were taken prisoner . Some of the prisoners were subsequently killed by the Germans , others were beaten and abused but survived and were eventually taken to POW camps . German losses are not known either . Official release by the Wehrmacht mentioned " several dozen dead " . It is however known that at least several hundred bodies of fallen German soldiers were exhumed from a local war cemetery . In his diaries general Heinz Guderian noted that 900 German soldiers were killed in action , although that number is probably underrated . The Wehrmacht lost at least 10 tanks and several other AFV s in the struggle . The history of the 10th Tank Division mentions for the 8th of September 9 KIA and 26 WIA for the ALA . The I . / IR 86 , which was the main unit of the capture of the bunkers reported on September 9 at 17 . 00 the loss of 40 men . There are some losses of the Tank Regiment 8 reported as well . The following fights at Wysokie - Mazowieckie and Andrzejewo make it difficult to differentiate the losses . In popular culture . Battle of Wizna is the theme of the song " 40 : 1 " , on the album " The Art of War " by the Swedish Metal band Sabaton . The title comes from the disparate ratio of forces and the lyrics compare the Polish forces with that of the legendary 300 Spartan warriors at the battle of Thermopylae .