Passage 8.11.5
κατὰ δὲ τὴν ἐς Παλλάντιον ἐκ Μαντινείας ἄγουσαν προελθόντι ὡς τριάκοντά που σταδίους, παρήκει κατὰ τοῦτο ἐς τὴν λεωφόρον ὁ τοῦ Πελάγους καλουμένου δρυμός, καὶ τὰ ἱππικὰ τὸ Ἀθηναίων τε καὶ Μαντινέων ἐνταῦθα ἐμαχέσαντο ἐναντία τῆς Βοιωτίας ἵππου. Ἐπαμινώνδαν δὲ ἀποθανεῖν Μαντινεῖς μὲν ὑπὸ Μαχαιρίωνος Μαντινέως φασὶν ἀνδρός· ὡσαύτως δὲ καὶ Λακεδαιμόνιοι Σπαρτιάτην λέγουσιν εἶναι τὸν ἀποκτείναντα Ἐπαμινώνδαν, τίθενται δὲ Μαχαιρίωνα ὄνομα καὶ οὗτοι τῷ ἀνδρί.
About thirty stadia along the road from Mantineia toward Pallantium, the grove called Pelagus extends to the highway. Here the cavalry forces of the Athenians and Mantineians fought against the Boeotian horsemen. The Mantineians say Epaminondas was killed by Machaerion, a Mantineian; likewise, the Lacedaemonians report that the slayer of Epaminondas was a Spartan, yet they, too, give this man the name Machaerion.