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.