The tract of flat land between the base of the mountains and the sea on the borders of the Gulf of Issus was nowhere broader than about a mile and a half.

The range of Amanus on the east rose up with rugged and broken hills, so that on this side the operations of cavalry were impracticable.

It would be impossible to form a line of battle containing in the front rank more than about 4000 men,1048 and difficult for either party to bring into action as many as 30,000 of their soldiers.

Thus the vast superiority of numbers on the Persian side became in such a position absolutely useless, and even Alexander had more troops than he could well employ.

No wonder that the Macedonian should exclaim, that "God had declared Himself on the Grecian side by putting it into the heart of Darius to execute such a movement." It may be that Alexander's superior generalship would have made him victorious even on the open plain of Sochi; but in the defile of Issus success was certain, and generalship superfluous.
Darius had started from Issus in pursuit of his adversary, and had reached the banks of the Pinarus, a small stream flowing westward from Amanus into the Mediterranean, when he heard that Alexander had hastened to retrace his stops, and was coming to meet him.