By following the course of Alexander's expedition upon the map at the commencement of chapter iii., it will be seen that his route lay first along the northern coasts of the Ægean Sea. He was to pass from Europe into Asia by crossing the Hellespont between Sestos and Abydos. He sent a fleet of a hundred and fifty galleys, of three banks of oars each, over the Ægean Sea, to land at Sestos, and be ready to transport his army across the straits. The army, in the mean time, marched by land. They had to cross the rivers which flow into the Ægean Sea on the northern side; but as these rivers were in Macedon, and no opposition was encountered upon the banks of them, there was no serious difficulty in effecting the passage. When they reached Sestos, they found the fleet ready there, awaiting their arrival.