German forces violated Polish borders in view of the utter exploitation of the effects of the operational and tactical surprise. Yet this plan failed, although the aggression was prepared in utmost secrecy. It turned that the well-organized defence of the objects, which were supposed to fall into invaders' hands after the first surprising attack, often surprised the invaders. First shots were fired in the fights for the Polish outpost in Westerplatte, and the Polish post office in Danzig. In both cases the Poles undertook a hopeless fight to manifest their determination to defend Polish rights and interests in the Free City Danzig. Also failed the attempt to seize an important railway communication running across the Polish Pomerania from the Reich to East Prussia. In Tczew Polish troops repelled the attack on the bridges across Vistula, and then blew them up; simultaneously in the west Polish troops frustrated an attempt to seize an important railway node in Chojnice.

In Upper Silesia the German command attached a special attention to the industrial facilities. The Germans wanted to seize them untouched and fully operational to enable their prompt switching to production for the German wartime needs. This task was assigned to well-organized subversive bands, which several hours before the outbreak of hostilities penetrated the Polish border, and together with the "fifth column" operating from within attacked coal mines, iron works and factories. Yet the attempt to surprise the Poles failed completely.

On the first day of the war also failed the German air forces - the Luftwaffe. On 1 September at 4:45 they flew across the Polish borders and headed towards Polish airfields. Bombs hit the airfields, but there were no Polish aircraft. From reserve airfields they took off for their first battle for the free sky over Poland. Dozens of German aircraft did not return from their first mission. Yet the Luftwaffe achieved a "complete success" while bombing open cities, defenceless villages and refugees in the Polish roads. The German navy - Kriegsmarine - was also prepared for an easy success. After all it had an overwhelming superiority over the Polish Navy. Yet the main forces of the Polish navy managed to sneak away from their bases and get to Great Britain.

Polish troops deployed along the northern and western frontiers delivered stubborn defence. There, near Mlawa, in Tuchola Forest and the Coast, along the upper Warta, in Silesia, and in the Carpathian foothills the battle for the north-western parts of the country was decided on 1 - 9 September. The Polish defence was broken through in the most vulnerable and operationally the most important sector between Klobuck and Czestochowa. Particularly hard fights took place near village Mokra, where fought the Volhynian Cavalry Brigade supported by blinded trains. Yet under the pressure of the prevailing enemy forces the brigade had to retreat to consecutive defence positions, and open the road to the Army Prusy being still formed and further - to Warsaw. On 5 September also exhausted possibilities to defend Silesia and Carpathian foothills, and the Supreme Command was forced to abandon the idea of defence along the main strategic position in western Poland. It made the decision to withdraw the bulk of the Polish forces beyond rivers Vistula and San.

The situation on the Germano-Polish front was worsening daily though. First of all the possibility of following the Supreme Command's orders was becoming more and more questionable. The Supreme Command wanted to rebuild the Polish defence along Vistula and San, but the ordered withdrawal of the troops proved impossible. German armoured and motorized troops were faster than Polish infantry units. Therefore the Germans won the race to the Vistula and San. Between 6 and 10 September there were undertaken attempts to halt the German advance with the forces of the reserve Army Prusy (Gen. Stefan Biernacki-Dąb). Yet this operation failed despite stubborn and dramatic defence near Piotrkow Trybunalski and Tomaszow Mazowiecki, and the southern wing of the army, fighting in the area of Kielce and Ilza, was encircled and cut off the passages across Vistula. On 7 September in the triangle Lodz - Plock - Warsaw found themselves surrounded three Polish armies: Pomorze (Gen. Władysław Bortnowski), Poznań (Gen. Tadeusz Kutrzeba), and Łódź (Gen. Juliusz Karol Rómmel), which were retreating from Pomerania, Posnania and upper Warta towards the passages across Vistula between Warsaw and Gora Kalwaria. Yet to the routes of their retreat got, or would soon get, the elements of the German 8th (Gen. Johannes Blaskowitz) and 10th (Gen. Walther von Reichenau) Armies. Any further retreat to Vistula through the tightening encirclement ring had to be forced in battle.

Meanwhile the Army Kraków (Gen. Antoni Szylling) after the stubborn fights in defence of Silesia was forced to retreat in face of the German 10th and 14th (Gen. Wilhelm List) Armies, whose armoured and light divisions were threatening with encirclement from the north. The army failed to rebuild the defence along rivers Nida and Dunajec. Together with the neighbouring Army Karpaty (later Małopolska - Gen. Kazimierz Fabrycy), it continued retreating beyond the San. However way earlier there were elements of the German 14th Army, which already on 5 September received the order to force the San and strike against the rears of the Polish defence on Vistula. There they had to co-operate with the armoured and motorized divisions from the Army Group North, which after the defeat of the Polish defence in Pomerania were moved to East Prussia. From there on 8 September they struck against the Polish positions near Wizna, where a 700-men-strong detachment under the command of Capt. Władysław Raginis fought gallantly for two days. After the break-through near Wizna the Germans ran to Brzesc. Meanwhile the 3rd Army (Gen. Georg von Küchler) on 9 September pierced the Polish defence on the lower Bug held (especially in vicinity of Mlawa) by the Army Modlin (Gen. Emil Przedrzymirski-Krukowicz). Across the lower Narew and Bug the Germans reached the eastern approaches of Warsaw.

Thus the attempt to build the new defence line along Bug, Vistula and San failed. The Supreme Command had decided to withdraw the bulk of the Polish forces to the south-east, where they were supposed to organize the new defence line along the Romanian border. They were supposed to hold the defence until the expected offensive of the Western allies and arrival of the war materials from France and England to the Romanian Black Sea ports. In the existing situation those were completely fantastic plans and they never came true.

On 8 September divisions from the German XVI Armoured Corps (Gen. Erich Höpner) reached the outskirts of the Polish capital - Ochota and Wola. They attacked the weak Polish forces not prepared yet for the defence. But the attempt to take Warsaw straight away failed. The fights turned into long siége of the city. And on 9 September started the battle of Bzura. The idea of fighting that battle came from the commander of the Army Poznań, Lt.Gen. Kutrzeba. He wanted to void the threat to Warsaw by an attack on the exposed left wing of the German armies. The operation started from the attack of the bulk forces of the Army Poznań on the German rears in the sector of Krosniewice - Brzeziny and with further advance on Lodz in view. Kutrzeba expected that the destruction of the German 8th Army would also open his troops the roads for further retreat eastward. Also the Army Pomorze took part in the operation: three infantry divisions were detached to create the Operation Group of General Edmund Kownacki-Knoll. Knoll's group entered the battle on 9 September. It rolled German 24th and 30th Infantry Divisions on river Bzura, inflicted heavy casualties on them and continued pursuit as far as to Strykow near Lodz. However, already on 12 September Gen. Kutrzeba decided to stop the advance in view of German counter-action with armoured troops and air forces, as well as growing own losses. Polish groups started regrouping towards Sochaczew, from where they had to launch a new attack to break through to Warsaw. To cover this manoeuvre the remnants of the Army Pomorze had to make a diversion in the sector Lowicz - Skierniewice. The German command sent more troops to the Bzura. With time the German superiority became overwhelming. On 16 September the Knoll's group started the advance, but instantly encountered strong armoured enemy troops and counter-action of the enemy air forces. It suffered a heavy defeat. Only residual forces of the two big Polish armies reached Warsaw. The third one, Army Łódź, was commanded by Gen. Wiktor Thommée after Gen. Rómmel lost contact with his troops. This army, which failed to reach the passages across Vistula, also headed for Warsaw. After stubborn but futile attempts to break through and bloody fights in Warsaw approaches it eventually diverted to Modlin. On 13 September the remnants of the army reinforced the defence of the fortress Modlin, which was already fighting with the advanced forces of the German II Corps. The same day the bulk forces of the II Corps approached Modlin from the north and north-west after having forced Bugo-Narew. From the formal point of view there were four divisions deployed in Modlin: 2nd Infantry (Colonel Antoni Staich), 28th Infantry (Colonel Stefan Bronowski), 30th Infantry (Colonel T. Furgalski), and 8th Infantry (Colonel Leopold Cehak). However, they were decimated and represented a strength no bigger than an infantry regiment. The Germans launched systematic assault on Modlin, and on 18 September they struck against Nowy Dwor. Heavy artillery and air raids supported their advance. The latter were particularly annoying, since the Polish fortress was practically defenceless against them.

Therefore by the mid-September the German command achieved its main strategic and operation objectives. The Polish army was not yet completely destroyed, but it was already surrounded and deprived of strengths and possibilities for operational counter-action. The enemy possessed complete command in the air, and complete control over the land operations. In those circumstances the forces of the Red Army entered Western Ukraine and Byelorussia, being at that time within the Polish borders, and advanced to the line limited by the German advance eastward. By night from 17 to 18 September the supreme state and military authorities abandoned the country and still fighting troops. Nevertheless the resistance did not extinguish yet.

The defence of Gdynia was entrusted to the Land Coastal Defence commanded by Colonel Dąbek. It was a loose grouping of 15 thousand troops organized into two regiments and one battalion of naval infantry, a brigade of National Defence, and other volunteer units. Military activities on the Coast began with German air forces' raids; on 1 September they attacked port installations, ships, the city and its vicinity. Then the German troops concentrated in the Free City Danzig launched land operations. By the night from 1 to 2 September it came to bloody fights near Kolibki. In result of the counter-attack of the 2nd Naval Infantry Regiment, which retook Kolibki and neighbouring hills, the enemy suffered heavy casualties. From there the Poles made surprising excursions into the enemy rears. By the night from 3 to 4 September with bigger forces they struck against the German positions near Osowa and Wysoka, killing or taking prisoners many enemy soldiers. When the German 4th Army broke through the defence in Pomerania and established communication between the Reich and East Prussia, German forces operating on the Coast were reinforced with the 207th Infantry Division. Hitlerites enjoyed substantial superiority in troops and artillery fire and their superiority in the air was overwhelming. However, despite of the superiority they made a rather lousy progress. It was not until 5 September that they took Kartuzy after bloody fights, which cost them a lot of casualties. Then in Wejherowo they encountered a hard defence of the 1st Naval Infantry Battalion. And there too they lost a lot of soldiers before they took the town on 8 September.

There the remnants of the Armies Kraków and Małopolska, which failed to rebuild the defence along middle Vistula and lower San, got encircled in the area of Krasnik - Bilgoraj. Gen. Tadeusz Piskor, who took command over those troops, decided to concentrate the bulk of his forces near Tomaszow Lubelski, pierce the German encirclement and march south-east. The core of the Polish assault grouping was built around the Varsovian Armoured Cavalry Brigade (Gen. Stefan Rowecki). On 17 September it struck against Tomaszow. Its first impetus broke the first line of the German defence, but its forces proved insufficient to develop the success. Meanwhile the Germans brought more reinforcements, and when on 18 September at dawn the Poles renewed the attack, it collapsed in face of the firm German defence. By night from 19 to 20 September, due to mounting casualties and lack of ammunition, Gen. Piskor decided to capitulate. He did not know that from the north there were coming the troops of the Army Lublin (Gen. Przedrzymirski-Krukowicz), composed of the remnants of the Polish troops of the Northern Front. Yet they engaged into closing fights near Krasnystaw and arrived to Tomaszow too late. On 21 September they started the second battle for the town, but the Germans, having made short with the Piskor's troops, now turned against Przedrzymirski. After heavy and bloody fights his troops capitulated on 26 September.

Other troops from the Army Małopolska, which avoided encirclement, were retreating towards Lwow, which was besieged as early as on 12 September. But on the river Wereszyca they encountered strong German grouping. On 19 - 20 September their fate was sealed. Yet it still was not the end of hostilities. Defenders of Lwow did not want to capitulate, although German envoys were repeatedly knocking to the gates promising a honourable captivity in exchange for capitulation. The command of the Lwow zone of defence was brought into being on 10 September. The commander of the Polish Southern Front, General Kazimierz Sosnkowski, entrusted command to General Prich and the command of the city defence to Colonel Fijałkowski, but they never assumed their duties, because the German advance reached Lwow earlier and rendered its organized defence impossible. Therefore General Władysław Langner assumed command of the defence of the surrounded city. The regular siége was started by the German 1st Highland Division on 12 September, when the city was not prepared for defence yet. People were hastily digging out cobblestones and raising barricades, when the approaches were closed by loose sections and platoons - altogether no more than a battalion. Five hundred men and 16 guns was all the city possessed for its defence at that moment. The enemy was halted in the suburbs, but it was just a reconnaissance in battle. They renewed their assault next day after a heavy air and artillery bombardment, and with bigger forces. They were engaged in bloody fights near Kulparkow and Kortumowa Gora. The Polish defence could collapse at any moment when a battalion from the 205th Infantry Regiment arrived from Dublany. Its soldiers under the command of Major Kraus were introduced to fights straight away and handled the situation. Kortumowa Gora remained in enemy hands, but the crisis was overcome. Although the enemy continued to attack, the defence was hardening. More regular troops arrived to Lwow, and popular militia, reservists and scout-boys reinforced them. Civilians took part in fortification works. There was no shortage of volunteers, but the defence experienced lack of arms and ammunition. The regiment of Lieutenant-Colonel Grefner got old French rifles Lebelle without ammunition, only with bayonets; others did not get even that.

Situation improved after arrival of units from the Operation Group Grodno, battalions of the 35th Infantry Division and anti-aircraft artillery. Lwow's garrison grew to 20 equivalent battalions, 65 field guns, and a dozen of anti-aircraft guns. Now General Langner decided not only to defend, but also to attack. So, regular sorties against the German rears started. They harassed the enemies and provided valuable reconnaissance data about deployment of their troops. On 15 September units from the 35th Infantry Division (Colonel Jarosław Szafran), supported by troops of Lt.Col. Grefner attacked the enemy at Kortumowa Gora and Holosko Wielkie. This attack, in which the Poles went to hand-to-hand fight, drove the Germans back and it was not stopped until they laid an artillery barrage. But the attack on Holosko Wielkie was renewed next day. In spite of the German superiority it improved the overall defence of the city. On 18 September a similar attack near Pirogowka frustrated German preparations for assault in that sector. Battalions under command of Lieutenant-Colonel Smreczyński took the village, while the 10th Armoured Cavalry Brigade (Colonel Stanisław Maczek) struck against the German rears in the Zamarstynow Hills.

On 19 September General Langner decided to make a diversion to relieve General Sosnkowski's divisions fighting in the Brzuchowiec Forest. Troops under command of Colonel Szafran took Zamarstynow and Holosko Male, but they failed to take Holosko Wielkie. The Germans introduced there fresh troops supported by tanks and air forces. They too were already stronger than in the beginning of the siége. Apart from the 1st Highland Division they also introduced in fights the 7th Infantry Division, 2nd Highland Division and tanks from the 5th Armoured Division; on the flanks they had German divisions from the XVII and XVIII Corps. On 20 September General Langner learnt that Sosnkowski's troops were crushed in unequal battle. Since then the besieged city could count only on its own strengths, and those were gradually shrinking and there was no hope for relief. Surrender to the Germans seemed inevitable, but meanwhile from the east approached Soviet troops. The chief of staff of the Lwow defence, Lt.Col. Kazimierz Ryziński, suggested a hand-over of the city to them. When Gen. Langner meet Soviet envoys, he told them: We are in war with the Germans - the city has been fighting gallantly for ten days. They, Germans, are the enemies of the Slavonic peoples. You are Slavs. [3]

On 21 September, after the collapse of Kutrzeba's counter-operation on Bzura, the XV Corps reinforced the German forces besieging Modlin. Its armoured units replaced there quite whipped infantry divisions from the II Corps. Preparations for a general assault started. But intensive air and artillery bombardment, which was supposed to soften the Polish defence, did not bring expected results. When on 27 September German troops launched the general assault, they were repelled with previous zeal. Next day the enemy attacked again, having reinforcements from the X Corps. The Poles did not give in until they expended the rest of food, water, ammunition and medicines for 4000 wounded. The command of the fortress came to conclusion that all the possibilities of efficient defence were exhausted and decided to surrender on the next day.

Still was fighting Warsaw, and smaller pockets of defence scattered every here and there. Individual Polish soldiers and their groups were still trying to reach the fighting capital. On 25 and 26 September Warsaw repelled the general assault of the storming German divisions. But another enemy - hunger and epidemics - was taking to the city from within. Eventually on 28 September the Polish capital capitulated. This decision came out both from the military reasons (mainly from the dramatic lack of artillery ammunition) and from the concern about the fate of about a million of inhabitants and refugees.

On 2 October Hel surrendered after a month of epic defence. A base of the Polish navy was located on the tip of the Hel Peninsula. Shortly before the war a decision was made to start building fortifications there. They were not finished yet, when the war broke out. The garrison of Hel numbered 2,800 men under the command of Commodore Włodzimierz Steyer. On 1 September at dawn first bombs fell on Hel; the peninsula was attacked by the infamous Junkers Ju-87 Stuka diver bombers. Till 9 September Hel was incessantly bombarded from the air and from the sea, but the Polish anti-air artillery and machine-guns successfully repelled all the attacks. The enemy suffered considerable losses. The coastal defence was equally successful. On 3 September, early in the morning, two German destroyers attacked the peninsula. They clashed with the Polish ships anchored in the port, as well as the batteries of the coastal artillery Canet and Henryk Laskowski. In result the destroyers sustained damages and retreated behind a smoke screen.

On 10 September in evening started the enemy land advance at Hel. On that day the 42nd Regiment of Border Guards (Grenzwache) and the 5th Cavalry Regiment from the Kaupisch Corps overcame weak Polish detachments of police and border guards at Swarzewo, and attacked Wielka Wies. There they encountered the defence of the airmen from the Sea Air Squadron, which halted the advance. However, the Poles withdrew from Wielka Wies as they were afraid of a German seaborne landing in their rear. Next day the Polish command decided to retake Wielka Wies. The counter-attack was launched at dawn. A daredevil assault promptly brought a success and inflicted losses at the enemy. Yet it was just the beginning. Now the hitlerites counter-attacked. Although the Germans possessed an overwhelming superiority in fire, Polish airmen and border guards drove back all the attacks. Then the Luftwaffe entered the fights. From low altitude German aircraft showered Polish positions with bombs and bullets. One plane was shot down, but the Poles had to withdraw to Wladyslawowo. A two-week pause in the fights occurred, during which the command of the defence conceived yet another bold plan. Namely they decided to turn the peninsula into an island. For that in the narrowest place, in Kuznica, a huge mine barrage had to be laid and blown up. A substantial number of torpedo warheads was stored practically useless. But they contained large charges of explosives and thus could be used as mines. The barrage was laid as planned: torpedo warheads were staggered across the peninsula at regular distances (10m) and connected with wires, which enabled remote electrical detonation.

On 21 September hitlerites renewed their advance at Hel. For two days they subjected the peninsula to an overwhelming bombardment by artillery, ships and air forces. They bestially bombed Kuznica, although there were no Polish troops; only civilians fell the victims of their barbarity. On 23 September the newly reinforced 374th Infantry Regiment launched reconnaissance in battle. It was supported by the barrage laid by German battleships Schleswig-Holstein and Schlesien from Danzig. On 25 September they left the port to conduct blank-point fire at Hel. Both battleships, escorted by a flotilla of minesweepers, were sailing at full speed along the peninsula when at 10:00 the defence spotted them. The battery Henryk Laskowski started the artillery duel; its 152mm guns were no match to the battleships' 280mm guns. The first salvo missed, but the next ones hit Schlesien. The minesweepers immediately laid a smoke screen; then the Poles aimed at Schleswig-Holstein. Meanwhile German fire demolished Hel, barracks and artillery emplacements. Two of four guns were destroyed and the commander of the battery, Capt. Zbigniew Przybyszewski was wounded. Nevertheless, the enemy was forced to withdraw. It was however the last success of the defence. On 30 September hitlerites renewed advance near Chalupy, where it came to hand-to-hand fights. Meanwhile other German troops landed in the Polish rear on both sides of the peninsula. Despite of repeated counter-attacks the situation was worsening. Under the pressure of the enemy troops and overwhelming fire defenders had to abandon all the consecutive positions, and pull back to Kuznica. There they eventually blew up 80 torpedo warheads, but the explosion proved inefficient. Although individual craters reached 2m in depth, they failed to cut the peninsula and the Germans managed to fill them very quickly. Step by step defenders were withdrawing towards Hel. They were at the end of their capabilities to fight; they lacked ammunition, food, medicines and warm clothes. In those circumstances Commodore Steyer made the decision to surrender.

The Independent Operation Group Polesie was the last regular Polish grouping fighting under command of Gen. Franciszek Kleeberg. When the Germans crossed the middle Bug and took Brzesc, the group was cut off the Polish forces fighting in the south-east. General Kleeberg decided then to march with aid to Warsaw. As they were moving towards Deblin, on 2 October they encountered the elements of the German XIV Motorized Corps (Gustav von Wietersheim) near Kock. Along the river Tysmienica unfolded fights, which ended on 6 October. The Poles were forced to capitulate, mainly due to lack of ammunition.

1. To prawda, że często gorzko na tej ziemi smakował więzienny chleb; lecz za tę rękę wzniesioną nad Polską - kula w łeb!
2. F. O. Busch, Unsere Kriegsmarine im Polnischen Feldzug
3. F. Bernaś, Najazd