Passage 5.4.7
Ἠλείοις δὲ μέτεστι μὲν πολέμου τοῦ πρὸς Ἰλίῳ, μέτεστι δὲ καὶ ἔργων τῶν κατὰ τὴν Μήδων ἐς τὴν Ἑλλάδα ἔφοδον. ὑπερβάντων δὲ ὅσοι σφίσιν ἐγένοντο κίνδυνοι πρὸς Πισαίους τε καὶ Ἀρκάδας ὑπὲρ τῆς διαθέσεως τοῦ ἀγῶνος τοῦ ἐν Ὀλυμπίᾳ, συν ες έβαλον μὲν Λακεδαιμονίοις ἀκουσίως ἐς τὴν Ἀθηναίων, συνέστησαν δὲ μετὰ οὐ πολὺν χρόνον ἐπὶ Λακεδαιμονίους Μαντινεῦσιν ὁμοῦ καὶ Ἀργείοις, ἐπαγόμενοι καὶ τὸ Ἀττικὸν ἐς τὴν συμμαχίαν.
The Eleans took part both in the Trojan War and in the later struggle of the Greeks against the Persian invasion. After overcoming the many dangers they faced from the Pisatans and Arcadians concerning the administration of the Olympic festival, they unintentionally sided with Sparta against Athens, but soon thereafter allied themselves with the Mantineans and Argives against the Spartans, even drawing Athens into this alliance.