Most of us know about the Battle of Westerplatte because it started WWII and involved one of the most storied ships of any navy, the Pre-Dreadnought Schleswig-Holstein.
Before we go further though, I want you to look over this map.
Now ponder the real story of the Battle of Westerplatte and ask yourself - what determines victory? What makes the difference? Do you make the most out of every post you have? Do you underestimate your enemy?
On September 1, 1939, at 0448 local time, Germany began its invasion of Poland, starting World War II; the Schleswig-Holstein suddenly opened broadside salvo fire on the Polish garrison held by 182 soldiers and 27 civilian reservists. Major Sucharski radioed Hel Peninsula "SOS: I'm under fire". Three holes were made in the perimeter wall and oil warehouses were blazing in the southeastern sector. Eight minutes later, Lieutenant Wilhelm Henningsen's crack marines storm unit from the Schleswig-Holstein advanced in three platoons while the Wehrmacht's Pioneers blew up the railroad gate going on the land-bridge, expecting an easy victory over the surprised Poles. Wojciech Najsarek, a Polish soldier, was killed by machine-gun fire, the first victim of both the battle and war. However, soon after crossing the artillery-breached brick wall, the attackers suddenly came into a well-prepared ambush. German soldiers found themselves caught in a kill zone of Polish crossfire from concealed firing points (the Germans believed they were also fired on by snipers hidden in the trees, but in reality that was not the case), while barbed wire entanglements effectively blocked quick movements. The Poles knocked out a machine gun nest at the German Schupo and Lt. Leon Pajak opened intense howitzer fire on the advancing Germans who faltered and stopped their attack. The Field gun knocked out sniper machine-gun nests on top of the warehouses across the canal and almost knocked out the Schleswig-Holstein's command post but was destroyed by the ship's guns.Even the Germans saw it - Fullbore.
At 0622, the Marines frantically radioed the ship they had heavy losses and were withdrawing, Danzig Police had tried to seize control of the harbor on the other side of Westerplatte but were defeated. Casualties were 50 Germans and 8 Poles. The Germans tried again at 0855 but met mines, fallen trees, barbed wire and intense fire. By noon the SS men fled and Henningsen was mortally wounded. The initial assault was crushed and a second attack that morning (after an artillery barrage of 90 280 mm shells, 407 170 mm shells and 366 88 mm shells) was repelled as well, the Germans suffering unexpectedly high losses. The Poles eventually retreated from the Wał and Prom outposts (and for a time also from Fort), tightening the ring of defence around the New Barracks in the centre of the peninsula. On the first day of combat, the Polish side lost one man killed and seven wounded (three died later, including two of them who were captured and died in a German hospital). On the other side, the German naval infantry lost 16 killed in action and some 120 wounded (injuries of various gravity), the majority out of the 225 men deployed. The German losses would have been even greater if not for the order by the Polish commander, Major Henryk Sucharski, for the mortar crews to cease fire in order to conserve ammunition, issued after firing just a few salvos (because of this order only 104 out of their 860 shells were spent when the mortars were destroyed on the next day).
On the following days, the Germans bombarded the peninsula with naval and heavy field artillery, including a 210 mm howitzer, turning it into World War I-style moonscape. Eberhardt convinced General Fedor von Bock a ground attack was not possible. A devastating two-wave air raid by 60 Junkers Ju 87 Stuka dive-bombers on September 2 (the total of 26.5 tons of bombs) took out the Polish mortars, directly hit guardhouse 5 (destroying it completely with a 500 kg bomb) and killed at least eight Polish soldiers; the air raid covered the whole area of Westerplatte in enormous clouds of smoke and destroyed their only radio and all their food supplies; German observers believed that no one could possibly have survived such bombing. On the night of 3–4 September more German attacks were repelled. On September 4 a German torpedo boat (T-196) made a surprise attack from the seaside. The "Wal" post had been abandoned and now only "Fort" position prevented an attack from the north side. On September 5, a shell-shocked Sucharski held a war council who urged Westerplatte was to surrender; his deputy, Captain Franciszek Dąbrowski, briefly took over command. Several cautious probing attacks by the German naval infantry, Danzig SS and police and Wehrmacht were again repulsed by the Poles; at 0300, during one of these attacks, they sent a firetrain against the land bridge, but failed when the terrified driver decoupled too early. It failed to reach the oil cistern and set ablaze the forest, valuable for cover. The flaming wagons gave a perfect field of fire and the Germans suffered heavy losses. A second fire-train attack came in the afternoon but it failed too. Instead in the meantime, Polskie Radio continuously broadcast the message "Westerplatte still fights on" in each morning of the battle. A second war council was held and the Major was set to surrender. After all, the German Army was now outside Warsaw and gangrene had started to appear among the wounded. At 0430 September 7, Germans opened intense fire on Westerplatte which lasted to 0700. Flamethrowers destroyed Guardhouse 2 and damaged 1 and 4. The besieged garrison lacked sufficient water and medical supplies; Cpt. Mieczysław Słaby, the WST medical officer, was unable to maintain basic care of wounded soldiers.
At 0945 the white flag appeared; the Polish defense impressed the Germans so much that the German commander, General Friedrich-Georg Eberhardt (who later became the military governor of Kiev during the Soviet-German War), allowed Sucharski to retain his ceremonial szabla (Polish sabre) in captivity (it was apparently confiscated later). At the same time Polish wireless operator Kazimierz Rasiński was murdered by Germans after the capitulation; after brutal interrogation, he refused to hand over radio codes and was shot.
Sucharski surrendered the post to Kleikamp and the Germans paraded in full order when the Polish garrison marched out, still proud and erect. In all, approximately 3,400 Germans were tied up by being engaged in the week-long action against the small Polish garrison.
The exact figures of German losses remain unknown, but are now often estimated to be in range of 200 to 300 killed and wounded or sometimes more. Some of them might be actually hit by friendly fire, in particular from the battleship which was initially anchored too close to its target. About 30-50 German troops were reportedly killed. Polish casualties were much lower, including 15 to 20 killed and 53 wounded. There's a controversy regarding the burial site discovered in 1940, containing the bodies of five unidentified Polish soldiers who were possibly executed by their comrades for attempted desertion. Eight of the prisoners of war also said to have not survived German captivity.