Passage 1.32.3
πρὶν δὲ ἢ τῶν νήσων ἐς ἀφήγησιν τραπέσθαι, τὰ ἐς τοὺς δήμους ἔχοντα αὖθις ἐπέξειμι. δῆμός ἐστι Μαραθὼν ἴσον τῆς πόλεως τῶν Ἀθηναίων ἀπέχων καὶ Καρύστου τῆς ἐν Εὐβοίᾳ· ταύτῃ τῆς Ἀττικῆς ἔσχον οἱ βάρβαροι καὶ μάχῃ τε ἐκρατήθησαν καί τινας ὡς ἀνήγοντο ἀπώλεσαν τῶν νεῶν. τάφος δὲ ἐν τῷ πεδίῳ Ἀθηναίων ἐστίν, ἐπὶ δὲ αὐτῷ στῆλαι τὰ ὀνόματα τῶν ἀποθανόντων κατὰ φυλὰς ἑκάστων ἔχουσαι, καὶ ἕτερος Πλαταιεῦσι Βοιωτῶν καὶ δούλοις· ἐμαχέσαντο γὰρ καὶ δοῦλοι τότε πρῶτον.
But before turning to a narrative about the islands, I will return once again to what concerns the demes. Marathon is a deme that lies equidistant from the city of Athens and from Carystus in Euboea. It was at this place in Attica that the barbarians landed, where they were defeated in battle and lost some ships during their retreat. In the plain there is a tomb of the Athenians, and upon it stand slabs inscribed with the names of the fallen, arranged according to their tribes. Another grave is for the Plataeans of Boeotia and for the slaves, because slaves fought then for the first time.