The Battle of the Hydaspes also known as Battle of Jhelum, or First Battle of Jhelum, was fought between the Macedonian Empire under Alexander the Great and the Pauravas under Porus in May of 326 BC. 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; Alexander spared Porus and made him a satrap, effectively reinstating him as the region's ruler.