The army, thus arranged and organized, advanced to the river. It was a broad and shallow stream. The Persians had assembled in vast numbers on the opposite shore. Some historians say there were one hundred thousand men, others say two hundred thousand, and others six hundred thousand. However this may be, there is no doubt their numbers were vastly superior to those of Alexander's army, which it will be recollected was less than forty thousand. There was a narrow plain on the opposite side of the river, next to the shore, and a range of hills beyond. The Persian cavalry covered the plain, and were ready to dash upon the Macedonian troops the moment they should emerge from the water and attempt to ascend the bank.