The origin of the Albanians has been the subject of historical, linguistic, archaeological and genetic studies. Albanians continuously first appear in the historical record in Byzantine sources of the 11th century. At this point, they were already fully Christianized. Albanian forms a separate branch of Indo-European, first attested in the 15th century, having evolved from one of the Paleo-Balkan languages of antiquity. The surviving pre-Christian Albanian culture shows that Albanian mythology and folklore are of Paleo-Balkanic origin and that almost all of their elements are pagan. Albanians have Paleo-Balkan origin. Theories which specifically they vary between attributing this origin to Illyrians, Thracians, Dacians, or another Paleo-Balkan people whose language was unattested; among those who support an Illyrian origin, there is a distinction between the theory of continuity from Illyrian times, and those proposing an in-migration of a different Illyrian population. These propositions are however not mutually exclusive. The Albanians are also one of Europe's populations with the highest number of common ancestors within their own ethnic group even though they share ancestors with other ethnic groups. Endonyms Arbëresh The two ethnonyms used by Albanians to refer to themselves are Arbëresh(ë)/Arbënesh(ë) (northwestern variant) and Shqiptar(ë). Arbëresh is the original Albanian ethnonym and forms that basis for most names of Albanians in foreign languages and the name of Albania as a country. Greek Arvanitai, Alvanitai and Alvanoi, Turkish Arnaut, Serbo-Croatian Arbanasi and others derive from this term. Different theories exist for the Ethnonym Shqiptar. Demiraj posits that Shqiptar derives from verb shqipoj (speak clearly) from Latin excipio (understand). It gradually replaced Arbëresh as the Albanian endonym by the end of the 18th century. The second theory is the idea that Shqiptar originated from the Scapudar family in medieval Drivastum is an early occurrence of the term. However this theory does not make chronological sense. Shqiptar from the Scapudar family is considered chronologically impossible. The third proposed etymology is that Shqiptar flows from the word shqiponjë (eagle). Its first attestation with its present meaning is in the dictionary of Francesco Maria da Lecce (1702) who addresses his readers as my "dear Shqipëtar" in its preface. This third theory matches the laws of Albanian word formation. Gudmund Shutte thought that "Skjipetar"(Shqiptar) was a corruption name of the Illyrian tribe Scirtari/Skirtones The ethnic name Albanian was used by Byzantine and Latin sources in the forms arb- and alb- since at least the 2nd century A.D,