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.