Then they shouted as a mixed multitude would shout when rejoicing; and most of them shed tears of joy. Some of them even approached the royal tent, and prayed for many blessings upon Alexander; because by them alone he suffered himself to be conquered. Then he divided the army into brigades, and ordered twelve altars to be prepared, equal in height to very large towers, and in breadth much larger than towers, to serve as thank-offerings to the gods who had led him so far as a conqueror, and also to serve as monuments of his own labours.[723] When the altars were completed, he offered sacrifice upon them according to his custom, and celebrated a gymnastic and equestrian contest. After adding the country as far as the river Hyphasis to the dominion of Porus, he marched back to the Hydraotes. Having crossed this river, he continued his return march to the Acesines, where he found the city which Hephaestion had been ordered to fortify, quite built. In this city he settled as many of the neighbouring people as volunteered to live in it, as well as those of the Grecian mercenaries who were now unfit for military service; and then began to make the necessary preparations for a voyage down the river into the Great Sea. At this time Arsaces, the ruler of the land bordering on that of Abisares, and the brother of the latter, with his other relations, came to Alexander, bringing the gifts which are reckoned most valuable among the Indians, including some elephants from Abisares, thirty in number. They declared that Abisares himself was unable to come on account of illness; and with these men the ambassadors sent by Alexander to Abisares agreed. Readily believing that such was the case, he granted that prince the privilege of ruling his own country as his viceroy, and placed Arsaces also under his power. After arranging what tribute they were to pay, he again offered sacrifice near the river Acesines. He then crossed that river again, and came to the Hydaspes, where he employed the army in repairing the damage caused to the cities of Nicaea and Bucephala by the rain, and put the other affairs of the country in order. BOOK VI. CHAPTER I. PREPARATIONS FOR A VOYAGE DOWN THE INDUS.