The pauravas was the name given to the many petty kingdoms and tribes of ancient NW India in the 5th and 4th centuries BCE. The Pauravas were all situated on or near the Indus river where their monarchs grew rich and prosperous through trade. The Persian kings Darius and Xerxes claimed suzerainty over many of the Pauravas, but this claim was loose at best. The most powerful tribes, those of Ambi and Porus were cowed by the Macedonian conqueror Alexander the Great in 326BCE, but he did not go on to conquer the entire area because his army simply refused to go any further. The region was eventually absorbed into the Mauryan empire.