The term "Kingdom of Denmark" is sometimes used to include both countries in the period, since the political and economic power emanated from the Danish capital, Copenhagen. These terms cover the "royal territories"

Origins of the Union
The three kingdoms Denmark, Norway and Sweden united in the Kalmar Union in 1397. Sweden broke out of this union and re-entered it several times, until 1521, when Sweden finally left the Union, leaving Denmark–Norway

Although the Dano–Norwegian union was generally viewed favourably in Norway at the time of its dissolution in 1814, some 19th-century Norwegian writers disparaged the union as a "400-year night". Historians describe the idea of a "400-year night" as a myth that was

Throughout the time of Denmark–Norway, it continuously had possession over various overseas territories. At the earliest times this meant areas in Northern Europe and North America, for instance Estonia and the Norwegian possessions of Greenland,

Differences between Denmark and Norway
After 1660, Denmark–Norway consisted of four formally separate parts (The Kingdom of Denmark

• Kingdom of Norway (1814)
• Military history of Denmark
• Military history of Norway
• Possessions of Norway
• Union between Sweden and Norway