The Battle of the Hydaspes also known as Battle of Jhelum, or First Battle of Jhelum, was fought between Alexander the Great and Porus in May of 326 BCE. It took place on the banks of the Hydaspes River in what is now the Punjab province of Pakistan, as part of Alexander's Indian campaign. In what was possibly their most costly engagement, the Macedonian army secured a decisive victory over the Pauravas and captured Porus. Large areas of Punjab were subsequently absorbed into the Macedonian Empire; Porus was reinstated as the region's ruler after Alexander, having developed a newfound respect for the fierce resistance put up by Porus and his army, appointed him as a satrap.