The Danes were a North Germanic tribe inhabiting southern Scandinavia, including the area now comprising Denmark proper, during the Nordic Iron Age and the Viking Age. They founded what became the Kingdom of Denmark. The name of their realm means "Danish March", viz. "the march of the Danes" in Old Low German, referring to their southern border zone between the Eider and Schlei rivers.
The origin of the Danes is unsettled, but several ancient historical documents and texts refer to them and archaeology has revealed and continues to reveal insights into their culture, beliefs, organization and way of life.
The Danes are first mentioned in the 6th century in Jordanes' Getica (551 AD), by Procopius, and by Gregory of Tours. They spoke Old Norse (dǫnsk tunga), which was shared by the Danes, the people in Norway and Sweden and later Iceland. In his description of Scandza, Jordanes says that the Dani were of the same stock as the Suetidi ("Swedes") and expelled the Heruli and took their lands.
The Old English poems Widsith and Beowulf, as well as works by later Scandinavian writers (notably by Saxo Grammaticus (c. 1200)), also provide some of the original written references to the Danes. According to the 12th century author Sven Aggesen, the mythical King Dan gave name to the Danes.