Now he had come to Pattala, and he thought of the victories he had gained and the countries he had annexed. He had appointed everywhere Greeks and Macedonians to rule in conjunction with the native princes and satraps.[10] The great empire must be knit together into a solid unity, and Babylon was to be its capital. Only in the west there was still an enormous gap to be conquered, the desert through which we have lately wandered on the way from Teheran through Tebbes and Seistan and Baluchistan. In order to reduce the people living here he despatched a part of his host by a northerly route through Seistan to north Persia. He himself led forty thousand men along the coast. Twelve thousand men were to sail and row the newly-built ships along the coast of the Arabian Sea, through the Straits of Hormuz, and along the northern coast of the Persian Gulf to the mouth of the Euphrates. No Greek had ever navigated this sea before, and with the vessels of the period the enterprise was a most dangerous one, as absolutely nothing was known about the coast to be followed. But it was necessary, for Alexander wished to secure for himself the command of the sea route between the mouths of the Euphrates and Indus, so as to connect the western and eastern parts of his kingdom. It was to supply the fleet with provisions and water that he chose for himself the dangerous desert route along the coast. Of the 40,000 men who accompanied him on this march, no less than 30,000 died of thirst! The high admiral, Nearchus of Crete, performed his task with brilliant success. His voyage was one of the most remarkable ever achieved on the oceans of the globe. The chart he compiled is so exact that it may be used at the present day, though the coast has since then undergone changes in some places and has been further silted up with sand and made shallower. Alexander would not let his fleet start on its adventurous voyage before he was himself convinced of the navigability of the Indus and had acquainted himself with the aspect of the great ocean. Accordingly he sailed down the western arm of the Indus with the swiftest vessels of the fleet--thirty-oared boats, and small triremes, or vessels whereon the 150 naked oarsmen sat on three tiers of benches above one another with oars of different lengths projecting through port-holes in the hull. The vessels were protected by troops which followed them on the bank.