How rogue commanders stalled the Nazi invasion

These sources detail the 1940 German invasion of Norway and the pockets of local resistance that emerged during the initial chaos. A primary focus is the Battle of Drøbak Sound, where Colonel Birger Eriksen’s command of Oscarsborg Fortress led to the sinking of the cruiser Blücher, a victory that delayed the capture of Oslo and allowed the Norwegian government to escape. The texts also highlight less conventional efforts, such as Thor Olaf Hannevig organizing a volunteer regiment to conduct delaying actions and the 25-day defense maintained at Hegra Fortress. While these individual operations did not ultimately halt the German occupation, the sources emphasize their strategic importance in preserving national leadership and demonstrating the impact of decisive local command. Collectively, the records provide a historical overview of how independent military units utilized aging coastal defenses and guerrilla tactics to challenge a superior invading force.