Conversation so far:
When did the Hellenistic period take place?
4th century BC.
Where were the Illyrians located?
Greco-Roman historiography.
Did the Illyrians have a Ruler/King/President?
The Illyrians formed several kingdoms in the central Balkans, and the first known Illyrian king was Bardyllis.
Were they peaceful or warlike?
After Philip II of Macedon defeated Bardylis (358 BC), the Grabaei under Grabos became the strongest state in Illyria.
Were there any other wars fought?
In the Illyrian Wars of 229 BC, 219 BC and 168 BC Rome overran the Illyrian settlements and suppressed the piracy that had made the Adriatic unsafe for Italian commerce.

Question: What happened after these wars?
Self-contained rewrite: What happened after the Illyrian Wars of 229 BC, 219 BC and 168 BC ?