Who were Ilirians?

Question

What language they had, why Romans killed all Ilirians, but that was not case with Macedonians, Greeks and others?!
Arheological evidences about Ilirians?

Answer 1

This article refers to the ancient inhabitants of the Balkans. For other uses of this word, see Illyria (disambiguation).
Illyrians has come to refer to a broad, ill-defined "Indo-European"[1] group of peoples who inhabited the western Balkans (Illyria, roughly from northern Epirus to southern Pannonia) and even perhaps parts of Southern Italy in classical times into the Common era, and spoke Illyrian languages. It is, however, less believable that in reality there was such a broad group that self-identified as Illyrians, and some argue that the ethnonym Illyrioi came to be applied to this large group of peoples by the ancient Greeks, Illyrioi having perhaps originally designated only a single people that came to be widely known to the Greeks due to proximity. Indeed, such a people known as the Illyrioi are supposed to have occupied a small and well-defined part of the south Adriatic coast, around Skadar Lake astride the modern frontier between Albania and Montenegro. The name may then have expanded and come to be applied to ethnically different peoples such as the Liburni, Delmatae, Iapodes, or the Pannonii.

Pliny in his Natural History applies a stricter usage of the term Illyrii, when speaking of Illyrii proprie dicti ("Illyrians properly so-called")[2] among the native communities in the south of Roman Dalmatia. A passage from Appian's Illyrike is representative of the broader usage of the term:

The Greeks call those people Illyrian who dwell beyond Macedonia and Thrace, from Chaonia and Thesprotia to the river Danube. —Appian, Illyrike 1

Answer 2

The Illyrians are mentioned for the last time in Miracula Sancti Demetri (7th century AD).[4] Many scholars conclude that the modern Albanians are the descendants of the Illyrians and that the Albanian language derives from the Illyrian language.

Romans were one culture with the Greeks, in fact the Greeks carried on the roman empire when the latin part of it dissolved under barbarian attacks.

Macedonians are just one of many greek tribes that lived near the Iirians so of course they would not be attacked as they were Greek and most likely were in the roman army... doing the attacking.

Answer 3

the Ilyrians were one of many ancient baltic peoples. their language is still unclear but it evident that it belongs to the indo-european language family and specifically to the baltic group.

I suggest referring to "Ancient Languages of the Balkans" by Katicic Radoslav.