Καὶ ἔστι καὶ τοῖσδε τοῖς αὐτοκράτορσιν ἐς τὸν παρόντα χρόνον ἐγγυτάτω διακοσίων ἐτῶν ἄλλων, ἐν οἷς ἥ τε πόλις μάλιστα κατεκοσμήθη καὶ ἡ πρόσοδος ἐπὶ πλεῖστον ηὐξήθη καὶ πάντα ἐν εἰρήνῃ μακρᾷ καὶ εὐσταθεῖ προῆλθεν εἰς εὐδαιμονίαν ἀσφαλῆ. καί τινα καὶ τοῖς προτέροις ἔθνεσιν οἵδε οἱ αὐτοκράτορες ἐς τὴν ἡγεμονίαν προσέλαβον καὶ ἀφιστάμενα ἄλλα ἐκρατύναντο. ὅλως τε δι’ εὐβουλίαν τὰ κράτιστα γῆς καὶ θαλάσσης ἔχοντες σώζειν ἐθέλουσι μᾶλλον ἢ τὴν ἀρχὴν ἐς ἄπειρον ἐκφέρειν ἐπὶ βάρβαρα ἔθνη πενιχρὰ καὶ ἀκερδῆ, ὧν ἐγώ τινας εἶδον ἐν Ῥώμῃ πρεσβευομένους τε καὶ διδόντας ἑαυτοὺς ὑπηκόους εἶναι καὶ οὐ δεξάμενον βασιλέα ἄνδρας οὐδὲν αὐτῷ χρησίμους ἐσομένους. ἔθνεσί τε ἄλλοις, ἀπείροις τὸ πλῆθος, αὐτοὶ διδόασι τοὺς βασιλέας, οὐδὲν αὐτῶν ἐς τὴν ἀρχὴν δεόμενοι· καὶ τῶν ὑπηκόων ἐνίοις προσαναλίσκουσιν, αἰδούμενοι καίπερ ἐπιζημίους ὄντας ἀποθέσθαι. τήν τε ἀρχὴν ἐν κύκλῳ περικάθηνται μεγάλοις στρατοπέδοις καὶ φυλάσσουσι τὴν τοσήνδε γῆν καὶ θάλασσαν ὥσπερ χωρίον.
(Appian, Rhōmaïka prooem. 7)
From the advent of the emperors to the present time is nearly two hundred years more, in the course of which the city has been greatly embellished, its revenue much increased, and in the long reign of peace and security everything has moved toward a lasting prosperity. Some nations have been added to the empire by these emperors, and the revolts of others have been suppressed. Possessing the best part of the earth and sea they have, on the whole, aimed to preserve their empire by the exercise of prudence, rather than to extend their sway indefinitely over poverty-stricken and profitless tribes of barbarians, some of whom I have seen at Rome offering themselves, by their ambassadors, as its subjects, but the chief of the state would not accept them because they would be of no use to it. They give kings to a great many other nations whom they do not wish to have under their own government. On some of these subject nations they spend more than they receive from them, deeming it dishonorable to give them up even though they are costly. They surround the empire with great armies and they garrison the whole stretch of land and sea like a single stronghold. (tr. Horace White)