Final answer:
Neutral countries north of Germany during World War II initially included Norway, Sweden, and Denmark. Their neutrality was disrupted by Germany's invasion, except for Sweden, which remained neutral throughout the war.
Step-by-step explanation:
The neutral countries located to the north of the German Empire during World War II were Norway, Sweden, and Denmark. Although Denmark and Norway were eventually invaded by Germany on April 9, 1940, at the beginning of the war, these countries attempted to maintain neutrality. Sweden managed to remain neutral throughout the war. The invasion of Denmark and Norway marked the expansion of the war to northern Europe and disrupted previous diplomatic efforts to maintain neutrality in that region. Sweden's successful maintenance of neutrality allowed it to avoid direct involvement in the conflict.