178 HISTORY OF GREECE. vude and warlike tribe called the Mardi ; but worse than any enemy was the severity of the season and the rugged destitution of a frozen country. Neither physical difficulties, however, nor human enemies, could arrest the march of Alexander. He re- turned from his expedition, complete master of Persis ; and in the spring, quitted that province with his whole army, to follow Darius into Media. He left only a garrison of 3000 Macedo- nians at Persepolis, preserving to Tiridates, wdio had surrender- ed to him the place, the title of satrap.^ Darius was now a fugitive, with the mere title of king, and with a simple body-guard rather than an army. On leaving Arbela after the defeat, he had struck in an easterly direction across the mountains into Media ; having only a few attendants round him, and thinking himself too happy to preserve his own life from an indefatigable pursuer.^ He calculated that, once across these mountains, Alexander would leave him for a time unmolested, in haste to march southward for the purpose of ap- propriating the great and real prizes of the campaign — Baby- lon, Susa, and Persepolis. The last struggles of this ill-starred prince will be recounted in another chapter. CHAPTER XCIV MILITARY OPERATIONS AND CONQUESTS OF ALEXANDER, AF- TER HIS WINTER-QUARTERS IN PERSIS, DOWN TO HIS DEATH AT BABYLON. From this time forward to the close of Alexander's life — a period of about seven years — his time was spent in conquering the eastern half of the Persian empire, together with various in- dependent tribes lying beyond its extreme boundary. Bui ' Curtius, V. 6, 11. * Arrian, iii. 16, 1-4.
