Parallel with the official criterion of Danish citizenship, other unofficial criteria for being a Dane exist. A commonly used criteria in this regard is having a Danish ancestral or ethnic identity. People living outside Denmark such as emigrants, and descendants of emigrants or members of the Danish ethnic minority in Southern Schleswig, Germany are sometimes considered to be Danes under a wider definition taking into consideration their cultural self-identification.
Modern Danish cultural identity is rooted in the birth of the Danish national state during the 19th century. In this regard, Danish national identity was built on a basis of peasant culture and Lutheran theology, with theologian N. F. S. Grundtvig and his popular movement playing a prominent part in the process. Two defining cultural criteria of being Danish was speaking the Danish language and identifying Denmark as a homeland.
The first mentions of tribal Danes are from the 6th century in Jordanes' Getica, by Procopius, and by Gregory of Tours. The first mention of Danes within the Danish territory is on the Jelling Rune Stone which states how Harald Bluetooth converted the Danes to Christianity in the 10th century. Denmark has been continuously inhabited since this period; and, although much cultural and ethnic influence and immigration from all over the world has entered Denmark since then, present day Danes tend to see themselves as ethnic descendants of the early tribal Danes mentioned in the historic sources. Whether this is true or not, the Danish Royal Family can certainly trace their family line back to Gorm the Old (d. 958 AD) in the Viking Age, and perhaps even before that to some of the preceding semi-mythical rulers.
The first mentions of "Danes" are recorded in the mid 6th century by historians Procopius (Greek: δάνοι) and Jordanes (danī), who both refer to a tribe related to the Suetidi inhabiting the peninsula of Jutland, the province of Scania and the isles in between. Frankish annalists of the 8th century often refer to Danish kings. The Bobbio Orosius from the early 7th century, distinguishes between South Danes inhabiting Jutland and North Danes inhabiting the isles and the province of Scania.