Pauravas was an ancient country in northwest subcontinent dating from at least 890 BCE. Its first capital was Hastinapura.
In the 8th century BCE, Hastinapura was destroyed by a severe flood and King Nikasu built a new capital, Kausambi. With the rise of the Mahajanapada powers, the state fell into a steady decline during 5th and 4th centuries BCE.
The origin of the Pauravas tribe is quite ancient and pre-dates MAHABHARATAS. The kings who descended from CHANDRA ("moon") were called CHANDRAVANSHI (or "of the lunar dynasty"). Yayati was a CHANDRAVANSHI king, with Puru and Yadu as two of his many sons. They were the founders of two main branches of the Chandravamsha; the YADUS, or Yadavas, were descendants of Yadu, and Pauravas were descendants of Puru.
The Pauravas had also existed earlier in the Vedic Ages. They were led by King Sudas, who fought off Persian invaders at the Battle of the Ten Kings.
The Pauravas were 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, led by Ambhi and Porus, were conquered by the Macedonian Emperor Alexander the Great in 326 BC. Porus fought a fierce last stand against Alexander at the Battle of the Hydaspes. Alexander was not able to conquer the entire area due to his army refusing to fight the Nanda Empire further east. By 322 BCE, the region had been conquered by Chandragupta Maurya, a teenage adventurer from Magadha, who later conquered the Nanda Empire and founded the Maurya Empire.