Also in the early 1500s Lutheranism was introduced and quickly adopted by the people of Denmark. This century also experienced war with Sweden to reassert dominance over the union, but Denmark failed in this task.
In the 1600s, the strong, and primarily German, Hanseatic League was loosening its monopoly on Scandinavian trading routes and cities as the Dutch rose in power and soon took control over North Sea and Baltic Sea trading. Also during this time the Swedes gained enough power that by the mid-1600s they entered Denmark and temporarily occupied parts of the country, although they failed to take all of Denmark.
The 1700s saw more battles with the Swedes, but no true border changes. In the late 1700s though Denmark again began to prosper as the country declared neutrality and focused on trading and economic progress over war and expansion.
The early 1800s again devastated Denmark as they sided with Napoleon's France during his wars throughout Europe. These battles, from the Danish perspective being primarily with Britain came at a huge coast and by the end of the Napoleonic wars, Denmark-Norway was bankrupt and Norway finally had the power to leave this union as they gained independence. However, in this agreement, Denmark took possession of Norway's territories of Iceland, Greenland, and the Faroe Islands. Also in the mid-1800s Denmark, shifted from an absolute monarchy to a constitutional monarchy and again claimed neutrality.