Alexander now embarked with his friends, and started on the voyage to the Southern Ocean. The bulk of the army simultaneously marched along the banks of the river under the command of Krateros and Hêphaistiôn. On coming to the place where the Akesinês and Hydaspês join each other the king landed his troops, and led them against a people called the Siboi. These, it is said, were descended from the soldiers who, under Heraklês, attacked the rock Aornos, and after failing to capture it were settled by him in this part of the country. Alexander encamped near their capital, and thereupon the citizens who filled the highest offices came forth to meet him, and reminded him how they were connected by the ties of a common origin. They avowed themselves to be, in virtue of their kinship, ready and willing to do whatever he might require, and presented him also with magnificent gifts. Alexander was so gratified by their professions of goodwill that he permitted their cities to remain in the enjoyment of their freedom.[356] He then advanced his arms against their next neighbours; and finding that the people called Agalassians[357] had mustered an army of 40,000 foot and 3000 horse, he gave them battle, and proving victorious put the greater number of them to the sword. The rest, who had fled for safety to the adjacent towns, which were soon captured, he condemned to slavery. The remainder of the inhabitants had been collected into one place, and he seized 20,000 of them, who had taken refuge in a large city, which he stormed. The Indians, however, having barricaded the narrow streets, fought with great vigour from the houses, so that Alexander in pressing the attack lost not a few Macedonians. This enraged him, and he set fire to the city, burning with it most of its defenders.[358] He gave quarter, however, to 3000 of the survivors, who had fled for refuge to the citadel and sued for mercy. _Chapter XCVII.—Disaster to the fleet at the confluence of the rivers_