The Periplus of Pseudo-Scylax, dating from the mid-fourth century BCE, makes a clear distinction between the Chaonians (the northernmost of the three Epirote tribes) and the Illyrian tribes.

The Illyrians and Chaonians appear to have had—at least at times—a confrontational relationship; Polybius recounts a devastating raid mounted in 230 BCE by the Illyrians against Phoenice, the chief city of the Chaonians.

The incident has major political ramifications.

Many Italian traders who are in the town at the time of the sacking are killed or enslaved by the Illyrians, prompting the Roman Republic to launch the first of the two Illyrian Wars the following year.