Illyrian Dialects
The Greeks were the first literate people to come into frequent contact with the speakers of Illyrian languages. Their conception of "Illyroi", however, differed from what the Romans would later call "Illyricum". The Greek term encompassed only the peoples who lived on the borders of Macedonia and Epirus. Pliny the Elder, in his work Natural History, applies a stricter usage of the term Illyrii when speaking of Illyrii proprie dicti ("Illyrians properly so-called") among the native communities in the south of Roman Dalmatia.
For a couple of centuries before and after the Roman conquest in the late 1st century BC, the concept of Illyricum expanded towards the west and north. Finally it encompassed all native peoples from the Adriatic to the Danube, inhabiting the Roman provinces of Dalmatia, Pannonia and Moesia, regardless of their ethnic and cultural differences. A passage in Appian's Illyrike stating that the Illyrians lived beyond Macedonia and Thrace, from Chaonia and Thesprotia to the Danube River, is representative of the broader usage of the term.
An extensive study of Illyrian names and territory was undertaken by Hans Krahe in the first decades of the twentieth century. He and other scholars argued for a broad distribution of Illyrian peoples considerably beyond the Balkans though in his later work, Krahe curbed his view of the extent of Illyrian settlement.
The further refinements of Illyrian onomastic provinces for that Illyrian area included in the later Roman province were proposed by Géza Alföldy. He identified five principal groups: (1) "real Illyrians" south of the river Neretva and extending south of the provincial boundary with Macedonia at the river Drin to include the Illyris of north and central Albania; (2) the Delmatae who occupied the middle Adriatic coast between the "real Illyrians" and the Liburni; (3) the Venetic Liburni of the northeast Adriatic; (4) the Japodes who dwelt north of the Delmatae and behind Liburni, where names reveal a mixture of Venetic, Celtic and Illyrian; and (5) the Pannonian people north in Bosnia, Northern Montenegro, and western Serbia.
These identifications were later challenged by Radoslav Katičić who on the basis of personal names which occur commonly in Illyricum distinguished three dialect areas: (1) South-Eastern Illyrian, extending southwards from the southern part of Montenegro and including most of Albania west of the river Drin, though its demarcation to the south remains uncertain; (2) Central Illyrian consisting of most of ex-Yugoslavia, north of southern Montenegro to the west of Morava, excepting ancient Liburnia in the northwest, but perhaps extending into Pannonia in the north; (3) Liburnian, whose names resemble those of the Venetic territory to the northeast.
The onomastic differences between the South-Eastern and Central areas are not sufficient to show that two clearly differentiated dialects of Illyrian were in use in these areas. However, as Katičić has argued, the core onomastic area of Illyrian proper is to be located in the southeast of that Balkan region, traditionally associated with the Illyrians (centered in modern Albania).
Read more about this topic: Illyrian Languages