Passage 6.12.3
οὗτος ὁ Ἱέρων ξενίαν πρὸς Πύρρον τὸν Αἰακίδου καὶ ὁμοῦ τῇ ξενίᾳ καὶ ἐπιγαμίαν ἐποιήσατο, Γέλωνι τῷ παιδὶ Νηρηίδα ἀγαγόμενος τὴν Πύρρου. Ῥωμαίων δὲ περὶ Σικελίας ἐς τὴν πρὸς Καρχηδονίους πόλεμον καταστάντων εἶχον μὲν οἱ Καρχηδόνιοι τῆς νήσου πλέον ἢ ἥμισυ, Ἱέρωνι δὲ συνιόντων μὲν ἄρτι ἐς τὸν πόλεμον ἑλέσθαι τὰ Καρχηδονίων ἤρεσε, μετὰ δὲ οὐ πολὺ δυνάμει τε εἶναι νομίζων τὰ Ῥωμαίων ἐχυρώτερα καὶ βεβαιότερα ἅμα ἐς φιλίαν μετεβάλετο ὡς τούτους.
This Hieron made ties of friendship with Pyrrhus, son of Aeacides, and along with friendship he also established a marital bond by marrying his son Gelon to Nereis, Pyrrhus' daughter. Later, when the Romans began their war against the Carthaginians over Sicily, the Carthaginians initially occupied more than half of the island. At first, as the war began, Hieron preferred to take the side of the Carthaginians; but, not long afterwards, considering the Roman strength superior and their position more secure, he changed his alliance and entered into friendship with Rome.