244 THE DECLINE AND FALL CHAP. Artaxerxes contained at least as great a number of ^^^^' cities, villages, and inhabitants. But it must likewise be confessed, that in every age the want of harbours on the sea coast, and the scarcity of fresh water in the inland provinces, have been very unfavourable to the commerce and agriculture of the Persians ; who, in the calculation of their numbers, seem to have indulged one of the meanest, though most common artifices of national vanity. Recapitula- As soon as the ambitious mind of Artaxerxes had wa° be-*'^ triumphed over the resistance of his vassals, he began tvveen the to threaten the neighbouring states, who, during the ai?d Roman long slumber of his predecessors, had insulted Persia empire. y^[^]^ impunity. He obtained some easy victories over the wild Scythians and the effeminate Indians ; but the Romans were an enemy who, by their past injuries and present power, deserved the utmost efforts of his arms. A forty years' tranquillity, the fruit of valour and mo- deration, had succeeded the victories of Trajan. Dur- ing the period that elapsed from the accession of Marcus to the reign of Alexander, the Roman and the Parthian empires were twice engaged in war; and although the whole strength of the Arsacides contended with a part only of the forces of Rome, the event was most commonly in favour of the latter. Macrinus, in- deed, prompted by his precarious situation and pusil- lanimous temper, purchased a peace at the expense of near two millions of our money ° ; but the generals of Marcus, the emperor Severus, and his son, erected many trophies in Armenia, Mesopotamia, and Assyria. Among their exploits, the imperfect relation of which would have unseasonably interrupted the more im- portant series of domestic revolutions, we shall only mention the repeated calamities of the two great cities of Seleucia and Ctesiphon. Cities of Se- Seleucia, on the western bank of the Tigris, about leucia and forty-five miles to the north of ancient Babylon, was the capital of the Macedonian conquests in Upper o Dion, 1. xxviii. p. 1335.
