Passage 1.11.2
Ἑλένου δὲ ὡς ἐτελεύτα Μολοσσῷ τῷ Πύρρου παραδόντος τὴν ἀρχὴν Κεστρῖνος μὲν σὺν τοῖς ἐθέλουσιν Ἠπειρωτῶν τὴν ὑπὲρ Θύαμιν ποταμὸν χώραν ἔσχε, Πέργαμος δὲ διαβὰς ἐς τὴν Ἀσίαν Ἄρειον δυναστεύοντα ἐν τῇ Τευθρανίᾳ κτείνει μονομαχήσαντά οἱ περὶ τῆς ἀρχῆς καὶ τῇ πόλει τὸ ὄνομα ἔδωκε τὸ νῦν ἀφʼ αὑτοῦ· καὶ Ἀνδρομάχης---ἠκολούθει γάρ οἱ---καὶ νῦν ἐστιν ἡρῷον ἐν τῇ πόλει. Πίελος δὲ αὐτοῦ κατέμεινεν ἐν Ἠπείρῳ, καὶ ἐς πρόγονον τοῦτον ἀνέβαινε Πύρρος τε ὁ Αἰακίδου καὶ οἱ πατέρες, ἀλλʼ οὐκ ἐς Μολοσσόν.
When Helenus died, having delivered authority to Molossus, son of Pyrrhus, Cestrinus, taking with him those Epeirotes who consented, occupied the territory beyond the river Thyamis; Pergamus went into Asia and, having engaged and slain Areius, who ruled in Teuthrania, in single combat over the sovereignty, gave the city its current name after himself. Andromache—for she accompanied him—still has a heroön in the city. Pielus remained behind in Epirus, and from this ancestor, rather than from Molossus, Pyrrhus, the son of Aeacides, and his forefathers derived their lineage.