Operation Weserübung was a significant military campaign undertaken by Nazi Germany to invade Denmark and Norway. The operation commenced in the early hours of April 9, 1940, aiming to secure both countries for strategic and resource-based reasons. Denmark was considered of little military importance but had crucial geographic significance that allowed Germany to control access to the North Sea. The German military launched a rapid assault, utilizing their Blitzkrieg tactics, which emphasized speed and coordination. Danish defenses crumbled within hours, and the country was occupied with little resistance.

Norway's invasion was more complex due to its challenging terrain and established military forces. Norway had been increasingly alert to German intentions; however, the direct assault caught them off guard. Key cities such as Oslo, Bergen, and Trondheim were swiftly captured by German forces, supported by Luftwaffe air superiority that decimated Norwegian defenses. The ultimate goal was to secure iron ore shipments from Sweden and prevent Allied forces from establishing a foothold in Scandinavia.

The invasions sparked an eventual bilateral conflict between German forces and Allied powers, including Great Britain and France, that sought to aid Norway. Over the ensuing months, Allied troops would attempt to interfere with German operations, leading to further military engagements in Scandinavia. The military engagements within both Denmark and Norway exemplified the implementation of blitzkrieg tactics, marking the beginning of significant German incursions into Northern Europe.