captain-price-officially:

The German cruiser Blucher goes down after sailing into the firing line of Norwegian coastal artillery and torpedo batteries, 9 April 1940

The Battle of Drøbak Sound took place in the northernmost part of the Oslofjord on 9 April 1940, on the first day of the German invasion of Norway. It was the start of the war in Western Europe—and an end to the “Phoney War”.
Oscarsborg Fortress near Drøbak engaged a German fleet sailing up the Oslofjord with the objective of seizing the Norwegian capital and capturing Haakon VII, the Norwegian king, and his government. At the time of the battle, the ageing fortress’ Main Battery of guns was over 40 years old and the installation had been relegated to training coastal artillery servicemen, leading the Germans to disregard the fortress’ defensive value. Furthermore, the most powerful weapon of the fortress was a torpedo battery, which no one but the Norwegian military knew about.
In the end, the fortress’ armament worked flawlessly. By sinking the lead ship of the German armada headed for Oslo, Oscarsborg Fortress saved the Norwegian king and government from being taken captive in the first hours of the invasion.

captain-price-officially:

The German cruiser Blucher goes down after sailing into the firing line of Norwegian coastal artillery and torpedo batteries, 9 April 1940

The Battle of Drøbak Sound took place in the northernmost part of the Oslofjord on 9 April 1940, on the first day of the German invasion of Norway. It was the start of the war in Western Europe—and an end to the “Phoney War”.
Oscarsborg Fortress near Drøbak engaged a German fleet sailing up the Oslofjord with the objective of seizing the Norwegian capital and capturing Haakon VII, the Norwegian king, and his government. At the time of the battle, the ageing fortress’ Main Battery of guns was over 40 years old and the installation had been relegated to training coastal artillery servicemen, leading the Germans to disregard the fortress’ defensive value. Furthermore, the most powerful weapon of the fortress was a torpedo battery, which no one but the Norwegian military knew about.
In the end, the fortress’ armament worked flawlessly. By sinking the lead ship of the German armada headed for Oslo, Oscarsborg Fortress saved the Norwegian king and government from being taken captive in the first hours of the invasion.

The Battle of Drøbak Sound took place in Drøbak Sound, the northernmost part of the outer Oslofjord in southern Norway, on 9 April 1940. It marked the end of the “Phoney War” and the beginning of World War II in Western Europe.
A German fleet led by the cruiser Blücher was dispatched up the Oslofjord to begin the German invasion of Norway, with the objective of seizing the Norwegian capital of Oslo and capturing King Haakon VII and his government. The fleet was engaged in the fjord by Oscarsborg Fortress, an ageing coastal installation near Drøbak, that had been relegated to training coastal artillery servicemen, leading the Germans to disregard its defensive value. However, unbeknownst to German military intelligence, the fortress’ most powerful weapon was a torpedo battery, which would be used to great effect against the German invaders.[14]
The fortress’ armaments worked flawlessly despite their age, sinking the Blücher in the sound and forcing the German fleet to fall back. The loss of the German flagship, which carried most of the troops and Gestapo agents intended to occupy Oslo, delayed the German occupation long enough for King Haakon VII and his government to escape from the capital.