The first mention of this state in official documents has been dated to 595, according to present knowledge. Some older historians cite a date of 745, while others claim one even later. The label of the first Slavic state is a topic of much controversy. Czechs proclaim to be descended from Great Moravia, which originated in 833.
Latin authors named the Gorostan (Mountain Home), a mountainous fatherland of Slovenian ancestors north of Karavanke with the name Carantanum. Carinthia can also be derived from the name for Carni, a Celtic people.
Dante Alighieri (1265-1321) mentions Karantania as Chiarentana. The same name was used by Florentines such as a poet Fazio degli Uberti (circa 1309-1367), the famous chronicler Giovanni Villani (1276-circa 1348) and Giovanni Boccaccio (1313-1375), who said that the river Brenta rises from the mountains of Karantania, that is a land in Alps, which divide Italy from Germany.
The ancient ritual of installing Karantanian dukes carried out in the Slovenian language on the Duke's Stone (Knežji kamen) at the Gosposvetsko polje (Gosposvetsko Field), today in Carinthia, Austria. This ceremony was conducted until the 15th century and it inspired Thomas Jefferson in writing the United States Declaration of Independence in 1776.