Passage 4.15.3
δῆλα οὖν ἐστιν ὡς ὕστερον τρίτῃ γενεᾷ τὸν πόλεμον οἱ Μεσσήνιοι τόνδε ἐπολέμησαν, ἀποδείκνυσί τε τοῦ χρόνου τὸ συνεχὲς βασιλεύοντας τηνικαῦτα ἐν Σπάρτῃ Ἀνάξανδρον Εὐρυκράτους τοῦ Πολυδώρου, τῆς δὲ οἰκίας τῆς ἑτέρας Ἀναξίδαμον Ζευξιδάμου τοῦ Ἀρχιδάμου τοῦ Θεοπόμπου. κατέβην δὲ ἐς ἀπόγονον Θεοπόμπου τέταρτον, ὅτι Ἀρχίδαμος ὁ Θεοπόμπου προαπέθανε τοῦ πατρὸς καὶ ἐς Ζευξίδαμον υἱιδοῦν ὄντα ἡ Θεοπόμπου περιῆλθεν ἀρχή. Λεωτυχίδης δὲ μετὰ Δημάρατον βασιλεύσας φαίνεται τὸν Ἀρίστωνος· Θεοπόμπου δὲ Ἀρίστων ἀπόγονος ἕβδομος.
It is therefore clear that the Messenians fought this war later, in the third generation afterward. The continuous sequence of time is demonstrated by the reign at that time in Sparta of Anaxander, son of Eurycrates, son of Polydorus, and from the other royal house Anaxidamus, son of Zeuxidamus, son of Archidamus, son of Theopompus. I have descended to the fourth descendant from Theopompus, because Archidamus, the son of Theopompus, died before his father, and thus the kingship passed to Zeuxidamus, the grandson of Theopompus. Leotychides is found reigning after Demaratus, the son of Ariston, and Ariston was the seventh descendant from Theopompus.