the ancient Greek name for the Jhelum River (also known as Vitatsa or Bihat) in India, a left tributary of the Indus River.
In 326 B.C. a battle took place on the left bank of the Hydaspes between the troops of Alexander the Great (30,000 men, including 5,000 cavalry) and those of the Indian ruler Poros (up to 34,000 men, including 3,000-4,000 cavalry, 300 battle chariots, 200 battle elephants). Leaving part of his forces on the right bank opposite Poros’ camp, Alexander, with the main part of his troops, forced the Hydaspes upstream, defeated a 2,000-man detachment sent against him, and forced Poros to flee his camp. In the unfolding battle, Alexander inflicted a blow with his cavalry on his opponent’s flanks and routed Poros’ troops, who suffered 23,000 killed.