earliest urban societies, the Indus Valley Civilization that flourished from about 3000 B.C. and declined rapidly 1,000 years later, following the Indo-Aryan migrations that overran the region in waves between 1500 and 500 B.C. Frequent intertribal wars stimulated the growth of larger groupings ruled by chieftains and kings, who ruled local kingdoms known as Mahajanapadas. The rise of kingdoms and dynasties in the Punjab is chronicled in the ancient Hindu epics, particularly the Mahabharata. The epic battles described in the Mahabharata are chronicled as being fought in what is now the state of Haryana and historic Punjab. The Gandharas, Kambojas, Trigartas, Andhra, Pauravas, Bahlikas (Bactrian settlers of the Punjab), Yaudheyas, and others sided with the Kauravas in the great battle fought at Kurukshetra. According to DrFauja Singh and Dr.L.M. Joshi: "There is no doubt that the Kambojas, Daradas, Kaikayas, Andhra, Pauravas, Yaudheyas, Malavas, Saindhavas, and Kurus had jointly contributed to the heroic tradition and composite culture of ancient Punjab." Invasions of Alexander the Great (c. 4th century BCE ) The earliest known notable local king of this region was known as King Porus, who fought the famous Battle of the Hydaspes against Alexander the Great. His kingdom spanned between rivers Hydaspes (Jhelum) and Acesines (Chenab); Strabo had held the territory to contain almost 300 cities. He (alongside Abisares) had a hostile relationship with the Kingdom of Taxila which was ruled by his extended family. When the armies of Alexander crossed Indus in its eastward migration, probably in Udabhandapura, he was greeted by the-then ruler of Taxila, Omphis. Omphis had hoped to force both Porus and Abisares into submission leveraging the might of Alexander's forces and diplomatic missions were mounted, but while Abisares accepted the submission, Porus refused. This led Alexander to seek for a face-off with Porus. Thus began the Battle of the Hydaspes in 326 BC; the exact site remains unknown. The battle is thought to be resulted in a decisive Greek victory; however, A. B. Bosworth warns against an uncritical reading of Greek sources who were obviously exaggerative. Alexander later founded two cities—Nicaea at the site of victory and Bucephalous at the battle-ground, in memory of his horse, who died soon after the battle. Later, tetradrachms would be minted depicting Alexander on horseback, armed with a sarissa and attacking a pair of Indians on an elephant. Porus refused to surrender and wandered about atop an elephant, until he