of the army, to make sure Porus would not find out about his crossing, while he crossed the river upstream with a strong contingent, consisting, according to the 2nd century AD Greek historian Arrian, of 6,000 on foot and 5,000 on horseback, though it was probably larger. Craterus was ordered to either ford the river and attack if Porus faced Alexander with all his troops or to hold his position if Porus faced Alexander with only part of his army. The other forces commanded by Meleager, Attalus, and Gorgias were ordered to cross the river in various places during the manoeuvre. Alexander's crossing of the Hydaspes in the face of Indian forces on the opposite bank was a notable achievement. The complex preparations for the crossing were accomplished with the use of numerous feints and other forms of deception. Porus was kept continuously on the move until he decided it was a bluff and relaxed. On every visit to the site of the crossing, Alexander made a detour inland to maintain the secrecy of the plan. It was also reported that there was an Alexander look-alike who held sway in a mock royal tent near the base. Alexander quietly moved his part of the army upstream and then traversed the river in utmost secrecy, using ‘skin floats filled with hay’ as well as ‘smaller vessels cut in half, the thirty oared galleys into three’. Furthermore, Craterus engaged in frequent feints suggesting that he may cross the river. As a result, Porus, 'no longer expecting a sudden attempt under cover of darkness, was lulled into a sense of security.' Alexander mistakenly landed on an island, but soon crossed to the other side. Porus perceived his opponent's manoeuvre and sent a small cavalry and chariot force under his son, also named Porus, to fight them off, hoping that he would be able to prevent his crossing. By chance a storm occurred that night which drowned out the sounds of the crossing. Having crossed the river, Alexander advanced towards the location of Porus's camp with all his horsemen and foot archers, leaving his phalanx to follow up behind. Upon meeting with young Porus's force, his horse archers showered the latter with arrows, while his heavy cavalry immediately charged without forming into line of battle. Young Porus also faced an unexpected disadvantage: his chariots were immobilized by the mud near the shore of the