Passage 1.13.2
μετὰ δὲ τὴν ἐν Ἰταλίᾳ πληγὴν ἀναπαύσας τὴν δύναμιν προεῖπεν Ἀντιγόνῳ πόλεμον, ἄλλα τε ποιούμενος ἐγκλήματα καὶ μάλιστα τῆς ἐς Ἰταλίαν βοηθείας διαμαρτίαν. κρατήσας δὲ τήν τε ἰδίαν παρασκευὴν Ἀντιγόνου καὶ τὸ παρʼ αὐτῷ Γαλατῶν ξενικὸν ἐδίωξεν ἐς τὰς ἐπὶ θαλάσσῃ πόλεις, αὐτὸς δὲ Μακεδονίας τε τῆς ἄνω καὶ Θεσσαλῶν ἐπεκράτησε. δηλοῖ δὲ μάλιστα τὸ μέγεθος τῆς μάχης καὶ τὴν Πύρρου νίκην, ὡς παρὰ πολὺ γένοιτο, τὰ ἀνατεθέντα ὅπλα τῶν Κελτῶν ἐς τε τὸ τῆς Ἀθηνᾶς ἱερὸν τῆς Ἰτωνίας Φερῶν μεταξὺ καὶ Λαρίσης καὶ τὸ ἐπίγραμμα τὸ ἐπʼ αὐτοῖς· τοὺς θυρεοὺς ὁ Μολοσσὸς Ἰτωνίδι δῶρον Ἀθάνᾳ
After the defeat in Italy, Pyrrhus rested his forces and then declared war upon Antigonus, bringing forward several accusations, and above all citing his failure to provide assistance in Italy. Having overcome both Antigonus's own troops and the Gallic mercenaries serving under him, Pyrrhus drove him to the coastal cities, and himself gained possession of Upper Macedonia and Thessaly. The magnitude of this battle and Pyrrhus's decisive victory, indicating how severe the conflict had been, is best demonstrated by the Celtic armor dedicated in the temple of Athena Itonia, situated between Pherae and Larissa, and by the inscription upon these weapons: "The Molossian dedicated these shields to Athena Itonia."