§2.1.1ἄρχεται δὲ ὁ πόλεμος ἐνθένδε ἤδη Ἀθηναίων καὶ Πελοποννησίων καὶ τῶν ἑκατέροις ξυμμάχων, ἐν ᾧ οὔτε ἐπεμείγνυντο ἔτι ἀκηρυκτεὶ παρ᾽ ἀλλήλους καταστάντες τε ξυνεχῶς ἐπολέμουν·
The war between the Athenians and the Peloponnesians and their respective allies begins from this point onward, during which they no longer had intercourse with one another without a herald, and, having entered into a state of war, fought continuously.
γέγραπται δὲ ἑξῆς ὡς ἕκαστα ἐγίγνετο κατὰ θέρος καὶ χειμῶνα.
It has been written down in order, as each event occurred, by summers and winters.