The Illyrian languages are a group of Indo-European languages that were spoken in the western part of the Balkans [1] in former times by ethnic groups identified as Illyrians: Delmatae, Pannoni, Illyrians, Autariatẽt, Taulanti.
Some sound-changes and other language features are deduced from what remains of the Illyrian languages, but because many writings in Illyrian are lost, it is difficult to clarify its place within the Indo-European language family. Because of the uncertainty, most sources provisionally place Illyrian on its own branch of Indo-European, though its relation to other languages, ancient and modern, continues to be studied.
http://en.wikipedia.org/wiki/Illyrian_languages