From 1536, after Sweden had broken out of the union, Norway entered into a closer dependency with Denmark in the kingdom of Denmark–Norway, which existed until 1814.
From the Middle Ages up until 1814, official Danish documents made clear that Greenland was a part of Norway.
Greenland as a dependency of the Kingdom of Denmark In 1814, Denmark-Norway found itself on the losing side of the Napoleonic Wars.
In gratitude to Sweden for its assistance in defeating Napoleon (and as a consolation for the recent loss of Finland to Russia), mainland Norway and certain Norwegian territories were transferred to Sweden — thus, the personal union of Norway and Denmark ended.
The dependencies of Greenland, Iceland and the Faroe Islands, however, remained part of the reorganised Kingdom of Denmark.