Stephanus of Byzantium is the only primary source who calls it a polis (πόλις ἐν ’Ιλλυριδι, pólis en ’Illyridi).
[11] Inscriptions at both Byllis and Nikaia begin in the middle of the 4th century BC and are related to a polis-like organization.
They are exclusively in Greek, as are institutions, the gods worshiped, the titles of the officials and other parts of the organization of the settlement.
[12] The Gods worshipped in Nikaia as well as Byllis are the typical deities of the Greek Pantheon: Zeus Tropaios, Hera Teleia, Poseidon, Parthenos,[a] etc.
[13] A 2nd-century BC inscription in a festival in Boetia, mentions an Illyrian contestant, Byllion from Nikaia (Βυλλίων απο Νίκαιας).
[2] A Hellenistic inscription records a strategos eponymos (Greek: Στρατηγός επώνυμος) a general of the Koinon of the Bylliones.