Whats up with all this talk about serbians, bosnians, and croatians being illyrians. Do any of these people speak a romance language?! I don't need anybody to answer that question because the answer is NO. What about the albanians? Neither do they. Let's take for example bosnians. Just because bosnians today live in a land previouly inhabited by illyrians, that doesn't make them descendants of illyrians. If they were descendants of illyrians, they wouldn't speak a south slavic language. If we were to go by linguistic grounds, then none of these 4 peoples can claim descent from illyrians. As far as the albanians go, there is a difference between albanians and serbians,bosnians and croatians. They predate the serbians, bosnians or croatians in the balkans. Serbian, bosnian and croatian are south slavic languages. Slavic languages are a recent arrival in the balkans that came with the arrival of slavs. As for albanian language, there is 3 possibilities, them being illyrian, thracian, or dacian. Illyrian seems the least likely possiblility, with thracian and dacian being most likely. Whether it's thracian or dacian, both thracians and dacians predate the slavs in the balkans by a long time. So serbs or any other slav for that matter have no right to claim any precedence over albanians in the balkans. Most believe that albanians were originally from a mountainous land. So what are they doing on the eastern coast of the adriatic? They were forced to move by westward and southward migrations of central asian people and slavs. The other option was to stay and get destroyed by populations that were way way bigger than the albanian populations.
You can see today's scientific studies, R1a in the Balkans is very, very old, oldest Balkan haplogroup, in Serbia, Bosnia, Macedonia over 10.000 years old. Today's Balkan I2a is about 2.300 year old. Of course there may be errors in the accurate estimations but do not change substance unless some new finding does not bring change.
For arrival of the Slavs in the Balkans in 6th century? According Y-DNA findings, it is third big movement R1a to Balkans. First movement was a long time ago (you have estimate), and another about 4.500 years.
And for Thracians. Maybe you read that a lot Thracian tribes are Serbs. For Thracian no doubt because it is described in history. Possible they were carriers of I2a (and R1a) haplogroup.
Who are Thracians, Illyrians etc. Only different tribes, not peoples or nations. And it is possible that same haplogroups these tribes are haplogroups Serbs, Macedonians, Bosniacs, Croats, who have almost same haplogroups and belong to the same genera.
When the Illyrians in question there is a mistake in understanding. Province Romana Illyricum and Greek Illyria are not same. Also, it can only be intrepreted as a geographical term. Term Illyrians may signify a collection of unrelated tribes that had possibly different haplogroups and spoke different languages. Possible that southern tribes were mostly E1b1b1a2. And also is possible that middle and north tribes were I2a+R1a. And that tribes among themselves did not have anything in common. Perhaps the Greeks called them by one name because they would otherwise have had to call each tribe separately. Researches Y-DNA of skeletions will give a more accurate picture.