Germany Begins Assault on Polish Forces in Hel

Hel was the target of air attacks from the first day of the campaign (1 September). The German army forced Polish units of Armia Pomorze to retreat from the Danzig Corridor in the first week of September, and began the assault of the Polish forces in Hel on 9 September. After Armia Pomorze was defeated in the Battle of Tuchola Forest, and other Polish strongholds on the coast capitulated (Battle of Westerplatte, Battle of Gdynia and Battle of Kępa Oksywska), from 20 September onward Hel was the only pocket of Polish resistance in northern Poland.

Hel defenders damaged a German destroyer on 3 September. Several Polish light minelayers laid a minefield near Hel in the night from 12 to 13 September. After some of them were sunk by Luftwaffe on the following day, due to German control of the Baltic Sea, the remaining units docked at Hel port and the crews joined the ground forces. The ships' armanents were stripped and converted into additional land gun emplacements. German naval units, including old battleships Schleswig-Holstein and Schlesien, shelled the Hel peninsula from 18 September, but with little effect. Schleswig-Holstein was lightly damaged by Polish coastal batteries on 25 September. Hel anti-aircraft batteries proved to be extremely efficient, shooting down between 46 and 53 German aircraft during the battle.

By September 14 Polish forces on Hel were cut off from the mainland. After being initially stalled by Polish defences, Germans brought land artillery batteries and an armored train battery to support their barrage. German forces slowly advanced, although they were still facing significant resistance and counterattacks. On September 25, after Germans took the village of Chałupy (today part of the town of Władysławowo), Polish military engineers detonated a number of torpedo warheads in the narrowest part of the peninsula, and for a time separated the peninsula from the mainland, transforming it into an island. On October 1, the commander of the Polish Navy, counter-admiral Józef Unrug, taking into consideration that the outpost was running out of supplies and that no relief force would be coming, gave the orders to capitulate. The Germans occupied the peninsula by October 2. After the capitulation of Hel, the only organized Polish resistance was carried out by Independent Operational Group Polesie, eventually defeated during the Battle of Kock.

At night on September 18th, Polish President and High Command along with a single battalion equipped with Renault R-35 (along with other units) entered Romania, where they were interned. On September 18th, Germans and Soviets met in Bresc nad Bugiem and exchanged "greetings". On October 2nd, Polish defenders of Hel (under Rear Admiral Unrug) capitulated, while last battle of the Polish campaign took place on October 2nd to 5th - Battle of Kock (Independent Operational Group Polesie under General Franciszek Kleeberg). On Friday, October 6th of 1939, last Polish troops capitulated.