A certain amount of success at first attended these measures. Memnon was able to act on the offensive in North-Western Asia. He marched upon Cyzicus and was within a little of surprising it, obtaining from the lands and villas without the walls an immense booty. He forced Parmenio to raise the seige of Pitane; and when Callas, one of the Macedonian leaders, endeavored to improve the condition of things by meeting the Persian forces in the open field, he suffered a defeat and was compelled to throw himself into Rhoeteum.
These advantages, however, were detrimental rather than serviceable to the Persian cause; since they encouraged the Persian satraps to regard the Macedonians as an enemy no more formidable than the various tribes of Greeks with whom they had now carried on war in Asia Minor for considerably more than a century. The intended invasion of Alexander seemed to them a matter of no great moment--to be classed with expeditions like those of Thimbron and Agesilaus, not to need, as it really did, to be placed in a category of its own. Accordingly, they made no efforts to dispute the passage of the Hellespont, or to oppose the landing of the expedition on the Asiatic shore. Alexander was allowed to transport a force of 30,000 foot and 4000 or 5000 horse from the Chersonese to Mysia without the slightest interference on the part of the enemy, notwithstanding that his naval power was weak and that of the Persians very considerable. This is one of those pieces of remissness in the Persian conduct of military matters, whereof we have already had to note signal instances, and which constantly caused the failure of very elaborate and judicious preparations to meet a danger. Great efforts had been made to collect and equip a numerous fleet, and a few weeks later it was all-powerful in the Egean. But it was absent exactly at the time when it was wanted. Alexander’s passage and landing were unopposed, and the Persians thus admitted within the Empire without a struggle the enemy who was fated to destroy it.
When the Persian commanders heard that Alexander was in Asia, they were anxious to give him battle. One alone, the Rhodian Greek, Memnon, proposed and urged a wholly different plan of operations. Memnon advised that a general engagement should be avoided, that the entire country should be laid waste, and even the cities burnt, while the army should retire, cut off stragglers, and seek to bring the enemy into difficulties. At the same time he recommended that the fleet should be brought up, a strong land force embarked on board it, and an effort made to transfer the war into Europe. But Memnon’s colleagues, the satraps and commandants of the north-western portion of Asia Minor, could not bring themselves to see that circumstances required a line of action which they regarded as ignominious. It is not necessary to attribute to them personal or selfish motives. They probably thought honestly that they were a match for Alexander with the troops at their disposal, and viewed retreat before an enemy numerically weaker than themselves as a disgrace not to be endured unless its necessity was palpable. Accordingly they determined to give the invader battle. Supposing that Alexander, having crossed into Asia at Abydos, would proceed to attack Dascyleium, the nearest satrapial capital, they took post on the Granicus, and prepared to dispute the further advance of the Macedonian army. They had collected a force of 20,000 cavalry of the best quality that the Empire afforded, and nearly the same number of infantry, who were chiefly, if not solely, Greek mercenaries. With these they determined to defend the passage of the small stream above mentioned--one of the many which flow from the northern flank of Ida into the Propontis.