In the meantime, however, Memnon had not been inactive, and he was putting to good use his superiority in naval strength. Several islands had either been occupied or were making preparations to join the Persian general, and even in continental Greece the anti-Macedonian influence was being felt. There was no question that Memnon’s arrival on the shores of European Greece would be the signal for a general abandonment of the Macedonian cause. Athens even sent an embassy to Darius, although the city did not dare to join the Persians openly. In the midst of these successes, Memnon was taken ill and died. Those who succeeded him in the command showed none of his capacity. The fleet was kept in inactivity, and though on land some small successes could be put to the credit of the Persian arms in Asia Minor, the soldiers operating there were soon directed to join the main army of Darius in Syria, now being collected to meet the advancing Greeks. When the news of Alexander’s victory at the Granicus reached the interior of the Persian Empire, Darius began to draw together a large army, and leaving Babylon in January, reached northern Syria in autumn. Alexander was still in Cilicia, detained in Tarsus by a severe illness, and on his recovery busied himself with the conquest of some of the coast cities. But when he heard of the advance of Darius, he marched trough the narrow pass near the coast which connects Cilicia and Syria, and commenced the siege of Myriandros, the first Phœnician city on the road. He evidently reckoned on Darius meeting him in the level places of northern Persia, where the latter’s cavalry could be used to its best advantage, but Darius showed a keener strategical instinct than is usually associated with Persian generalship. While Alexander was taking the coast road south, Darius’ army made a northerly movement, passing over a difficult mountain region, and so appeared in the rear of the Macedonian army on the level plain near Issus. The Persians had a strong position; on their right was the sea, and on their left a chain of mountains. On the front they were protected by the deeply worn bed of the river Pinarus. They had also constructed a line of earthworks. The preliminary operations of the Persians were conducted with great intelligence. By them Alexander was cut off from his base and his position was desperate, unless he could restore his line of communications by a successful engagement. This was no easy matter, for the mountain defile, the Assyrian Gate, had to be passed through, a place where the mountains and the sea are so close that there is room only for a road. Darius had an excellent position but failed to make any use of it. Without attempting to interfere he allowed Alexander to march through the narrow strip of land between the mountains and the sea and to change from a column formation into regular battle array.