[3,44] Ἕτερον δέ τι τοῦ προειρημένου πολιτεύματος κρεῖττον, ὃ καὶ τοῖς κατὰ τὸν βίον ἅπασιν εὐδαιμονεστέραν αὐτὴν ἐποίησε καὶ πραγμάτων ἐπῆρεν ἅψασθαι γενναιοτέρων. τοῦ γὰρ Τεβέριος ποταμοῦ καταβαίνοντος μὲν ἐκ τῶν Ἀπεννίνων ὀρῶν, παρ´ αὐτὴν δὲ τὴν Ῥώμην ῥέοντος, ἐμβάλλοντος δ´ εἰς αἰγιαλοὺς ἀλιμένους καὶ προσεχεῖς, οὓς τὸ Τυρρηνικὸν ποιεῖ πέλαγος, μικρὰ δὲ καὶ οὐκ ἄξια λόγου τὴν Ῥώμην ὠφελοῦντος διὰ τὸ μηθὲν ἐπὶ ταῖς ἐκβολαῖς ἔχειν φρούριον, ὃ τὰς εἰσκομιζομένας διὰ θαλάττης καὶ καταγομένας ἄνωθεν ἀγορὰς ὑποδέξεταί τε καὶ ἀμείψεται τοῖς ἐμπορευομένοις, ἱκανοῦ δὲ ὄντος ἄχρι μὲν τῶν πηγῶν ποταμηγοῖς σκάφεσιν εὐμεγέθεσιν ἀναπλεῖσθαι, πρὸς αὐτὴν δὲ τὴν Ῥώμην καὶ θαλαττίαις ὁλκάσι μεγάλαις, ἐπίνειον ἔγνω κατασκευάζειν ἐπὶ ταῖς ἐκβολαῖς αὐτοῦ λιμένι χρησάμενος αὐτῷ τῷ στόματι τοῦ ποταμοῦ. εὐρύνεταί τε γὰρ ἐπιπολὺ τῇ θαλάττῃ συνάπτων καὶ κόλπους λαμβάνει μεγάλους, οἵους οἱ κράτιστοι τῶν θαλαττίων λιμένων· ὃ δὲ μάλιστα θαυμάσειεν ἄν τις, οὐκ ἀποκλείεται τοῦ στόματος ὑπὸ τῆς θαλαττίας θινὸς ἐμφραττόμενος, ὃ πάσχουσι πολλοὶ καὶ τῶν μεγάλων ποταμῶν, οὐδ´ εἰς ἕλη καὶ τέλματα πλανώμενος ἄλλοτε ἄλλῃ προκαταναλίσκεται πρὶν ἢ τῇ θαλάττῃ συνάψαι τὸ ῥεῖθρον, ἀλλὰ ναυσιπέρατός ἐστιν ἀεὶ καὶ δι´ ἑνὸς ἐκδίδωσι τοῦ γνησίου στόματος ἀνακόπτων τὰς πελαγίους ῥαχίας τῆς θαλάττης, καίτοι πολὺς αὐτόθι γίνεται καὶ χαλεπὸς ὁ πνέων ἀπὸ τῆς ἑσπέρας ἄνεμος. αἱ μὲν οὖν ἐπίκωποι νῆες ὁπηλίκαι ποτ´ ἂν οὖσαι τύχωσι καὶ τῶν ὁλκάδων αἱ μέχρι τρισχιλιοφόρων εἰσάγουσί τε διὰ τοῦ στόματος αὐτοῦ καὶ μέχρι τῆς Ῥώμης εἰρεσίᾳ καὶ ῥύμασι παρελκόμεναι κομίζονται, αἱ δὲ μείζους πρὸ τοῦ στόματος ἐπ´ ἀγκυρῶν σαλεύουσαι ταῖς ποταμηγοῖς ἀπογεμίζονταί τε καὶ ἀντιφορτίζονται σκάφαις. ἐν δὲ τῷ μεταξὺ τοῦ τε ποταμοῦ καὶ τῆς θαλάττης ἀγκῶνι πόλιν ὁ βασιλεὺς ἐντειχίσας, ἣν ἀπὸ τοῦ συμβεβηκότος Ὠστίαν ὠνόμασεν, ὡς δ´ ἂν ἡμεῖς εἴποιμεν θύραν, οὐ μόνον ἠπειρῶτιν, ἀλλὰ καὶ θαλαττίαν παρεσκεύασε τὴν Ῥώμην γενέσθαι καὶ τῶν διαποντίων ἀγαθῶν ἔγευσεν.

[3,44] Another peace-time achievement was of even greater consequence than the one just mentioned, as it made the city richer in all the conveniences of life and encouraged it to embark upon nobler undertakings. The river Tiber, descending from the Apennine mountains and flowing close by Rome, discharges itself upon harbourless and exposed shores made by the Tyrrhenian Sea; but this river was of small and negligible advantage to Rome because of having at its mouth no trading post where the commodities brought in by sea and down the river from the country above could be received and exchanged with the merchants. But as it is navigable quite up to its source for river boats of considerable seize and as far as Rome itself for sea-going ships of great burden, he resolved to build a seaport at its outlet, making use of the river's mouth itself for a harbour. For the Tiber broadens greatly where it unites with the sea and forms great bays equal to those of the best seaports; and, most wonderful of all, its mouth is not blocked by sandbanks piled up by the sea, as happens in the case of many even of the large rivers, nor does it by wandering this way and that through fens and marshes spend itself before its stream unites with the sea, but it is everywhere navigable and discharges itself through its one genuine mouth, repelling the surge that comes from the (p179) main, notwithstanding the frequency and violence of the west wind on that coast. Accordingly, oared ships however large and merchantmen up to three thousand bushels burden enter at the mouth of the river and are rowed and towed up to Rome, while those of a larger size ride at anchor off the mouth, where they are unloaded and loaded again by river boats. Upon the elbow of land that lies between the river and the sea the king built a city and surrounded it with a wall, naming it from its situation Ostia, or, as we should call it, thyra or "portal"; and by this means he made Rome not only an inland city but also a seaport, and gave it a taste of the good things from beyond the sea.