During various Ages of Migration, the Jutes, Angles and Saxons invaded and settled in Britain. The modern country they came from is Denmark. Not that they would have known. The broader idea of Denmark only came in the 10th century as a Kingdom unified. The various sea-faring cultures fought for control of the Baltic Sea. Like Muhammad formed the idea of a unified Muslim Ummah (community) out of warring tribes, the Germanic tribes wouldn't have seen themselves as Germanic tribes. Unity tends to come when someone powerful happens to also be able to tell a good story that is better than lingering vendettas. Denmark includes two constituent countries - The Faroe Islands and Greenland. It was once united with Norway and Sweden in the Kalmar Union. It is among the founding members of the European Union, NATO, the Nordic Council, and the United Nations. Identities change when interests change.