Alexander crossed the Hellespont in the spring of the year 334 B.C., and first encountered the Persians near the Granikos River. The battle was decisive although the losses on either side do not appear to have been heavy. It was but the augury of what was to follow. The subsequent advance of the Macedonian troops southward through the lovely land of Iona, and the reduction of Miletus and Helikarnassos, brought the first year's campaign to a close. The second year opened with the conquest of Pamphyllia and Phrygia, the passage of the Tauros ranges being made in winter. On the return of spring he recrossed the Tauros and reduced the western hill-tribes of Kilikia. Part of his force, meanwhile, had occupied the passes into Syria known as the Syrian gates. Within two days march of the Syrian gates the Persian hosts again were massed in an open plain under Darius, who had advanced from the east, waiting to fall upon the Macedonian troops and crush them as they debouched from the defile. Tired of waiting, however, Darius moved forward into Kilikia by the Amanian passes to look for Alexander, and thus it happened that when Alexander finally emerged from the Syrian gates into the plains of Syria he found his enemy behind him. He partially retraced his steps and regained the pass by midnight, and there from one of the adjoining summits he "beheld the Persian watch-fires gleaming far and wide over the plain of Issos." The rapidity of Alexander's movements was only equalled by the fierce energy of his onslaught when he led his cavalry against the unwieldy formations of his Persian enemy. It was his own hand that gained the victory both then and afterwards.
There is no more stirring story in all history than this progress of the Macedonian force. Step by step it has been traced out from Granikos to Issos and from Issos to Arbela; but this is not the place to recapitulate that part of the story which applies only to Western Asia. It is not until after the final decisive battle at Arbela, when Darius fled in hot haste along the south-eastern road to Ecbatana, the former capital of Media, and thence in the spring of 330 B.C. retreated with a disorganized force and an intriguing court towards Baktria, where he hoped to find a refuge with his kinsman Bessos the satrap of that province, that we really touch on the subject with which we wish to deal in this book, viz. the high-roads to Afghanistan in those long past days. Alexander, meanwhile, had received the submission of Babylon and restored the temple of Belus, and made himself master of a more spacious empire than the world had yet seen. It was then that the amazing results of his military success began to turn his head. From this point the severe simplicity of the Macedonian soldier is exchanged for the luxury, arrogance, and intolerance of the despot and conqueror. As Alexander advanced in material strength so did he slide down the easy descent of moral retrogression, and whilst we can still admire his magnificence as a military leader we find little else left to admire about him. From Babylon to the lovely valley wherein lies Susa, and from Susa to Persepolis, was more or less of a triumphal march in spite of the fierce opposition of the satrap Artobaizanes. Of Persepolis we are taught to believe that Alexander left nothing behind him but blackened ruins--the result of a drunken orgy. During the winter, amidst snow and ice, he subdued the Mardians in their mountain fastnesses (for he never left an active foe on the flank or rear), and with the return of the sweet Persian spring he renewed his hunt after Darius, turning his face to the north and east.