Passage 2.9.2
συμβαλὼν δὲ περὶ Δύμην τὴν ὑπὲρ Πατρῶν, Ἀράτου καὶ τότε ἡγουμένου τῶν Ἀχαιῶν, νικᾷ τῇ μάχῃ. τοῦτο Ἄρατον ἠνάγκασεν ὑπέρ τε Ἀχαιῶν καὶ αὐτῆς Σικυῶνος δείσαντα Ἀντίγονον ἐπάγεσθαι. Κλεομένους δὲ παραβάντος ἣν πρὸς Ἀντίγονον συνέθετο εἰρήνην καὶ παράσπονδα ἐκ τοῦ φανεροῦ καὶ ἄλλα δράσαντος καὶ Μεγαλοπολίτας ποιήσαντος ἀναστάτους, οὕτω διαβάντος ἐς Πελοπόννησον Ἀντιγόνου συμβάλλουσιν Ἀχαιοὶ Κλεομένει περὶ Σελλασίαν. νικησάντων δὲ τῶν Ἀχαιῶν Σελλασία τε ἠνδραποδίσθη καὶ αὐτὴ Λακεδαίμων ἑάλω. Λακεδαιμονίοις μὲν οὖν ἀπέδωκεν Ἀντίγονος καὶ Ἀχαιοὶ πολιτείαν τὴν πάτριον·
Joining battle near Dyme, which is situated beyond Patrae, with Aratus again commanding the Achaeans, he (Cleomenes) was victorious in the engagement. This forced Aratus, who became fearful for both the Achaeans and his own city of Sicyon, to call upon Antigonus for aid. However, as Cleomenes soon broke the truce he had arranged with Antigonus, openly violating his word and committing other outrages, and causing the people of Megalopolis to be driven from their homes, Antigonus crossed into the Peloponnese. Then the Achaeans confronted Cleomenes in battle around Sellasia. After the victory of the Achaeans, Sellasia was made captive, and Sparta itself fell. Consequently, Antigonus and the Achaeans restored to the Lacedaemonians their ancestral form of government.