Denmark has been inhabited by various Germanic peoples since ancient times, including the Angles, Cimbri, Jutes, Herules, Teutones and others.

[28] A 2025 study in Nature found genetic evidence of an influx of central European population after about 500 ce into the region later ruled by the Danes.

Around the same time, he received a visit from a German missionary who, by surviving an ordeal by fire according to legend, convinced Harold to convert to Christianity.

The Reformation, which originated in the German lands in the early 16th century from the ideas of Martin Luther (1483–1546), had a considerable impact on Denmark.

Those who had traveled to Wittenberg in Saxony and come under the influence of the teachings of Luther and his associates included Hans Tausen, a Danish monk in the Order of St John Hospitallers.

[28] After a failed war with the Swedish Empire, the Treaty of Roskilde in 1658 removed the areas of the Scandinavian peninsula from Danish control, thus establishing the boundaries between Norway, Denmark, and Sweden that exist to this day.

In the centuries after this loss of territory, the populations of the Scanian lands, who had previously been considered Danish, came to be fully integrated as Swedes.

The Danish liberal and national movements gained momentum in the 1830s, and after the European revolutions of 1848 Denmark became a constitutional monarchy on 5 June 1849.

[32] As a concept, det danske folk (the Danish people) played an important role in 19th-century ethnic nationalism and refers to self-identification rather than a legal status.

In this regard, Danish national identity was built on a basis of peasant culture and Lutheran theology, with Grundtvig and his popular movement playing a prominent part in the process.

A minority of approximately fifty thousand Danish-identifying German citizens live in the former Danish territory of Southern Schleswig (Sydslesvig), now located within the borders of Germany, forming around ten percent of the local population.

Due to immigration there are considerable populations with Danish roots outside Denmark in countries such as the United States, Brazil, Canada, Greenland and Argentina.