Denmark is one of the oldest nations; it was established as a Christian kingdom by Harald Bluetoooth in 965.
In the 8th to 10th centuries, the Danes were called Vikings which Peter pronounces Wikings. Along with Swedish and Norwegian raiders they pretty much went where they wanted and took what they liked, but also settled, often with local patronage in England, Ireland and Wales. Although her family is entirely Irish back to Niall of the Nine Hostages, my mother's mtDNA is Swedish.
This is the oldest, Medieval area of Copenhagen; parts of which are prudently entirely pedestrian.